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LECTURES  ^ 


ON 


I     GEOLOGY; 

BEING  OUTLINES  OF  THE  SCIENCE, 

DELIVERED    IN 

THE  NEW-YORK  ATHEN^UM. 

In  the  year  1825. 
BY 

JER.,|VAN  RENSSELAER,  M.  D^ 

i  \ 
Associate,  and  Lecturer  nn  frfttlogy  in  the.  *Athe.na>mnt 

Member  of  the  Royal  Medical  Soc.  Edin. ;  Cor.  Memb.  of  the  Royal  Aca- 
demy of  Sciences,  Naples;  of  the  Linnean  Soc. — of  the  Society  of  Encou- 
ragement, and  of  the  Medico-physic.  Soc.  Fans;  Director  of  the  American 
Academy  of  Fine  Arts ;  Cor.  Sec'y.  of  the  Lyceum  of  Natural  History,  and 
of  the  New  York  Horticultural  Soc,  Sec'y-  of  the  Liter,  and  Philosop.  Soc. 
and  Member  of  the  Historical  Soc.  New  York ;  Member  of  the  Soc.  of 
Natural  History,  Leipzic— of  the  Soc.  for  promotion  of  Arts,  and  Cor.  of 
the  Lyceum,  Albany. 


NEW-YORK  : 

PUBLISHED  BY  E.  BLISS  &  E!  WHITE,    128  BROADWAY. 
H.  SPEAR,  PRINTER* 

sp 

1825. 


of  New-  York,  ss. 

BE  IT  REMEMBERED,  That  on  the  fourteenth  day  of  May,  A.  If- 
1825,  in  the  forty  ninth  year  of  the  Independence  of  the  United  States  of 
America,  E.  Bliss  &E.  White,  of  said  District,  have  deposited  in  this  office 
the  title  of  a  Book,  the  right  whereof  they  claim  as  Proprietors,  in  the  words 
following,  to  wit : 

"  LECTURES  ON  GEOLOGY:  being  outlines  of  the  Science,  delivered 
in  the  New-York  Athenaeum,  in  the  year  1825.  By  Jer.  Van  Rensselaer, 
M.  D.  Associate,  and  Lecturer  on  Geology  to  the  Athenaeum,  Member  of 
the  Royal  Medical  Sco.  Edin. ;  Cor.  Memb.  of  the  Royal  Academy  of 
Sciences,  Naples ;  of  the  Linnean  Soc. — of  the  Society  of  Encourage- 
ment, and  of  the  Medico-physic.  Soc.  Paris ;  Director  of  the  American 
Academy  of  Fine  Arts:  Cor.  Sec'y.  of  the  Lyceum  of  Natural  History,  and 
of  the  New  York  Horticultural  Soc.  Sec'y.  of  the  Liter.  andPhilosop.  Soc. 
and  Member  of  the  Historical  Soc.  New  York  ;  Member  of  the  Soc.  of 
Natural  History,  Leipzic — of  the  Soc.  for  promotion  of  Arts,  and  Cor.  of 
the  Lyceum,  Albany. 

In  conformity  to  the  Act  of  Congress  of  the  United  States,  entitled  "  An 
Act  for  the  encouragement  of  Learning,  by  securing  the  copies  of  Maps, 
Charts,  and  Books  to  the  authors  and  proprietors  of  such  copies,  during  the 
time  therein  mentioned."  And  also  to  an  Act,  entitled  "  An  Act,  suple- 
mentary  to  an  Act,  entitled  an  Act  for  the  encouragement  of  Learning,  by 
securing  the  copies  of  Maps,  Charts,  and  Books  to  the  authors  and  proprie- 
tors of  such  copies,  during  the  time  therein  mentioned,  and  extending  the 
benefits  thereof  to  the  arts  of  designing,  engraving,  and  etching  historical 
and  other  prints." 

JAMES  DILL, 
Clerk  of  the  Southern  District  of  New-York. 


TO 

MY  FELLOW  ASSOCIATES 
OF  THE 


THIS  WORK  IS  DEDICATED, 

AS  A  MARK  OF  RESPECT 
FOR  THE  HONOURABLE  ZEAL 

AND     . 

DISINTERESTED  VIEWS 

THEY  HAVE  MANIFESTED 
XN  ESTABLISHING  THE  INSTITUTION, 


LIST  OF  ASSOCIATES, 


Rev.  W.  Harris,  D.  D.  PRESIDENT. 


H.  J  Anderson,  M.  D. 
R.  Adrain,  L.  L.  D. 
Prof.  Charles  Anthon, 
H.  Brevoort,  Jr.  Esq. 
Rev.  M.  Bruen, 
Rev  C.  D.  Barry, 
Rev.  W.  Berrian, 
Jas.  Cooper,  Esq. 
Win.  Cooper,  Esq. 
Hon.  C.  C.  Cambreling, 
N.  H.  Carter,  Esq. 
Hon.  C.  D.  Golden, 
John  Delafield,  Esq. 
Jos.  Delafield,  Esq. 
J.  E.  DeKay,  M.  D. 
J.Duer,  Esq. 
Rev.  C.  R.  Duffie, 
A.  B.  Durand,  Esq. 
Rev.  M.  Eastburn, 
T.  A.  Emmet,  Jr.  Esq. 
J.  W.  Francis,  M.  D. 
Col.  G.  Gibbs, 
R.  GreenhowM,  D. 
Wm.  Gracie,  Esq. 
John.  Griscom,  L.  L.  D. 
A  Halsey,  Esq. 
D.   Hosack,  M.  D. 
F.  G.  Halleck,  Esq. 
J.  A.  Hilhouse,  Esq. 
Gen.  C.  G.  Haines, 
Hon.  P.  A.  Jay, 
Rt.  Rev.  J.  Hobart,  D.  D. 
J.  S.  Hone,  Esq. 
J.  J.  Jones,  Esq. 
Hon.  J.  Kent,  L.  L.  D. 
Hon.  Rufus  King, 
Charles  King,  Esq. 
F.G.  King,M.  D. 
E.  G.  Ludlow,  M.  D. 
W.  B.  Lawrence,  Esq. 


S.  L.  Mitchill,  M.  D. 
Prof.  J.  Me.  Vickar, 
Rev.  P.  Milledoler,  D.  D. 
Prof.  N.  F.  Moore, 
W.  J.  Macneven,  M.  D. 

B.  Me  Vickar,  M.  D. 

C.  C.  Moore,  Esq. 

Rev.  J.  M.  Mathews,  D.  D. 
W.  Moore  Esq. 
S.  W.  Moore,  M.  D. 
A.  Me  Vickar,  Esq. 
Gen.  J,  Morton, 
Hon.  J.  J.  Morgan, 
Rev.  J.  Milnor,  D.  D. 
Rev.  B.  T.  Onderdonk, 
W.  Post,  M.  D. 
J.  M.  Pendleton,  M.  D. 
J.  K.  Paulding,  Esq. 
M.  Payne,  M.  D. 
Prof.  J.  Renwick, 
J.  S.  Rogers,  M.  D. 
J.  R.  Rhinelander,  M.  D, 
P.  Rhinelander,  Esq. 
Rev.  J.  F.  Schroeder, 
R.  C.  Sands,  Esq. 
Rev.  F.  C.  Schaeffer, 
D.  Seldon,  Esq. 
A.  H.  Stevens,  M.  D. 
J.  A.  Stevens,  Esq. 
Rev.  W.  D.  Snodgrass, 
Rev.  S.  H.  Turner,  D.  D. 
J.  Torry,  M.  D. 
Jer.  Van  Rensselaer  M.D, 
Hon.  G.  C.  Verplank, 
J.  Verplank,  Esq. 
Rev.  J.M .  WainwrightDD. 
H.  Wheaton,  L.  L.  D. 
Rev.  W.  Ware, 
J.  Watts,  Jr.  M.  D 


PATRONS  OF  THE  NEW-YORK  ATHENJEUM, 


David  Andrews, 
David  Austen, 
Wm.  Adee, 
James  Boggs, 
Hendrick  Booraem, 
Francis  Barretto  Jr. 
Wm.  Bayard, 
C.  J.  Burckle, 
W.  G.  Bucknor, 
J.  Balestier 
H.  Booraem, 
Cornelius  Baker, 
Isaac  Carow, 
Duncan  P.  Campbell, 
John  S.  Crary, 
John  G.  Coster, 
Henry  Cotheal, 
Russell  Comstock, 
William  B.  Crosbv. 
W.  W.  Chester,  * 
F.  A.  Clark, 
Peter  Crary, 
Lyne  Catlin, 
B.  Clarke, 
John  Delafield 
F.  Depeyster,  Jr. 
Thomas  Dixon, 
William  W.  Deforest, 
Edward  C.  Delavan, 
Samuel  Downer,  Jr. 
Samuel  E.  Foote, 
Joseph  Foulke, 
Jonathan  Goodhue, 
Edward  M.  Greenwav, 


Robert  Gill, 
Frederick  Gebhard, 
John  Glover, 
Andrew  Gray, 
George  Griffin, 
R.  Gedney, 
George  Griswold, 
Thomas  H.  Hutchinson. 
Goold  Hoyt, 
Issac  S.  Hone, 
James  Heard, 
Peter  Harmony, 
David  Hadden. 
John  Hone, 
Philo  Hillyer, 
Fisher  How, 
John  Haggerty, 
John  Hone,  Jr. 
William  Howard, 
G.  G.  Howland, 
Samuel  S.  Howland 
Isaac  Jones,  Jr. 
J.  Sheppard  James, 
Jeromus  Johnson, 
William  Israel, 
John  Johnson, 
Ebenezer  Irving, 
Henry  Kneeland, 
Joseph  Kernochan 
Morgan  Lewis, 
Hugh  Laing, 

Augustine  H.  Lawrence. 
Jno.  W.  Leavitt, 
Dominick  Lvnch  Jr. 


Vll. 


Kutus  L.  Lord, 
Archibald  M'Vickar, 
John  A.  Moore, 
A.  S.  Marvin, 
Benjamin  Marshall, 
George  Newbold, 
Russel  H.  Nevins, 
Samuel  Neilson, 
Francis  Olmsted, 
Ralph  Olmstead, 
William  Osborne, 
Nathaniel  Prime, 
Henry  Post,  Jr. 
Walter  Phelps, 
John  R.  Pitkin, 
Ellis  Potter,      ", 
Thadeus  Phelps, 
Moses  Rogers, 
Nathaniel  Richards, 
Elisha  Riggs, 
Peter  Remsen, 
John  A.  Stevens, 
Peter  Schermerhorn, 
Henry  D.  Sewall, 
William  Stevens, 
Paul  Spoflford, 
Henry  Shelters, 


Jr. 


Jos.  S.  Shotwell, 
Thomas  Sands, 
Thomas  H.  Smith, 
John  Stewart,  Jr. 
J.  W.  Schmidt, 
Thomas  Tileston, 
James  Thompson, 
Arthur  Tappan, 
Francis  Thompson, 
Jeremiah  Thompson, 
Henry  Dodd, 
M.  Van  Schaick, 
William  L.  Vandervoort, 
P.  L.  Vandervoort, 
A.  H.  Van  Bokkelen, 
Ezra  Weeks, 
William  W.  Woolsey, 
Samuel  Ward  Jr. 
William  Watkinson, 
Samuel  Whittemore, 
William  Weyman 
Charles  Wilkes, 
John  G.  Warren, 
Nathaniel  Weed, 
Stephen  Whitney, 
R.  D.  Weeks. 


GOVERNORS. 


William  B.  Astor, 
Henry  Brevoort,  Jr. 
James  Byers, 
F.  W.  H.  Broadman, 
Robert  Bayard, 
Henry  Barclay, 
Theodorus  Bailey, 
William  Banks., 
J.  Boorman, 
Joseph  Blackwell, 
Henry  Cary, 
Charles  F.  Codwise, 
Chester  Clark, 
Levi  Coit, 
Henry  C.  Dunham, 
James  D'Wolf,  Jr. 
John  Ferguson, 
George  Gallagher, 


Samuel  Glover, 
S.  H.  Goodell, 
David  Hosack, 
Philip  Hone, 
Joseph  Hudson, 
Isaac  C.  Jones, 
Edward  R.  Jones, 
Moses  Judah, 
Robert  Kermit, 
Isaac  Lawrence, 
Anson  Livingston, 
Gillian  Ludlow, 
David  R.  Lambert, 
A.  Legget, 
Chailes  Lawton, 
J.  E.  Mowatt, 
Samuel  Marsh, 
John  Nesmith, 


Vlll. 


Joseph  Nicholls, 
Smith  Pyne, 
W.  Renwick, 
Robert  Ray, 
J.  J.  Rjoosevelt,  Jr. 
B.  W.  Rodgers, 
W.  A.  Rhodes, 
John  Rogers, 
Edward  N.  Rogers, 
J.  Rathbone,  Jr. 
Leunan  Reed, 
Charles  D.  Rhodes, 


Frederick  Sheldon, 
Alexander  H.  Stevens, 

F.  W.  Steinbrenner, 
Abraham  Schermerhorn, 
Joseph  Sampson, 
Robert  Sedgwick, 

W.  W.  Titus, 
H.  B.  Titus, 
Eli  Vail, 
John  Watts,  Jr. 

G.  W.  Wallis. 


When  the  Lecturship  on  Geology  was  instituted 
in  the  New  York  Athenaeum,  it  was  not  supposed 
that  the  class  of  students  would  exceed  30  or  40 
young  persons,  novices  in  the  science.  The  bril- 
liant success  that  has  attended  the  establishment 
of  the  Institution  was  not  then  anticipated.  It  was 
with  no  small  degree  of  reluctance  and  timidity 
therefore  that  the  Lecturer  addressed  a  large  and 
enlightened  audience.  Nor  was  that  timidity  less 
than  the  satisfaction  he  afterwards  experienced, 
on  being  advised  by  those  who  are  admitted  to  be 
capable  of  judging,  to  submit  the  Lectures  to  the 
public. 

The  Lecturer  has  been  the  more  willing  to  pub- 
lish  these  outlines,  since  in  this  country,  Geology 
is  generally  considered  as  embracing  a  knowledge 
of  rocks  merely,  or  positive  geognosy ;  whereas, 
that  study,  though  a  very  interesting  and  valuable 
one,  is,  in  fact,  but  a  part  of  the  science.  There 
is  no  work  published,  it  is  believed,  that  even  hints 
at  the  many  important  points  properly  treated  of 
under  the  head  of  geology  :  most  authors  on  this 


subject  having  confined  themselves  to  Theories 
and  Rocks.  Nor  is  there  any  work  that  from  its 
size  and  arrangement  and  authority  is  well  calcu- 
lated to  be  placed  in  the  hands  of  the  student. 
It  is  hoped  that  the  present  volume,  while  it  offers 
in  the  plainest  possible  language,  a  more  extend- 
ing outline  of  the  science,  is  sufficiently  condensed 
for  that  purpose ;  and  that  it  will  fill,  in  some 
measure,  the  gap  so  universally  acknowledged  to 
exist,  until  a  more  general  and  more  able  produc- 
tion shall  supercede  it. 

It  is  by  no  means  intended  to  impress  upon  the 
reader  a  belief  that  these  Lectures  are  the  re- 
sult of  personal  observation.  On  the  contrary, 
much  of  what  is  found  in  the  following  pages  is  dis- 
tributed through  the  writings  of  preceding  enqui- 
ries. Numerous  and  extensive  opportunities  for 
the  study  of  geological  phenomena  in  Europe  and 
America  may  have  given  the  Lecturer  some  right 
to  form  his  own  opinions  ;  yet  as  these  have  gene- 
rally coincided  with  the  ideas  of  others,  liberal  re- 
sort haslbeen  made  to  Humboldt,  Macculloch, 
Conybeare,  and  Phillips,  &c.  &c.  and  it  is  believed 
that  a  comparison  of  the  views  and  observations  of 
such  philosophers  will  vouch  for  every  fact  stated 
in  this  work.  ,T.  V.  R 

Feb.  22d  1825 


CONTENTS. 

LECTURE  1. 

introductory  remarks — 'Divisions  of  Natural  His- 
tory— Geological  theories — Stewart's  opinion 
of  theories — Fontanelle's,  Bailly's.  Theory 
of  Burnett — Protogaea  of  Leibnitz.  Theories  of 
Wooodward,  Hook,  Hally,  Whiston,  Lazoro 
Moro,  De  la  Pryme,  King,  Deluc,  Guettard, 
Lister,  Lehman,  Whitehurst,  Kirwan,  Buffbn, 
Button,  Saussure,  Pallas,  Werner — Observations 
on  the  theories  of  Huttori  and  Werner.  Deluge, 
traditions  of  it.  American  Geologists.  Striking 
coincidences  between  Sacred  History  and  the 
discoveries  of  Geology 13 

LECTURE  II. 

Objects  of  Geology — its  utility  to  the  farmer,  min- 
er and  architect.  Position  of  Rocks — division 
of  them  into  classes — Observations  on  the  Pri- 
mary Rocks,  on  the  Transition,  the  Secondary, 
the  Tertiary,  and  Alluvial.  Organic  remains. — 
Divisions  of  the  Earth's  Surface — Bottom  of  the 
Sea — Dryland,  Lowland — Alpine  land — Moun- 
tain Groups  and  chains — Observations  on  the 
position  and  declivities  of  mountains— -Val- 
lies  54 


X11  CONTENTto. 

LECTURES  III. 

Changes  produced  on  the  Earths  surface,  by  the 
formation  of  Peat,  &,c. — Coral  reefs — Volca- 
noes— Observations  on  their  structure,  position, 
&c. — Vesuvius — Etna — Sabrina — Earthquakes, 
those  of  Lisbon  and  Calabria — Volcanic  Fire — 
its  Intensity,  Situation  and  Origin  .  .  95 

LECTURE  IV. 

Minerals  entering  into  the  composition  of  Rocks — 
Different  forms  of  Rocks  —masses,  beds,  strata, 
nodules,  veins — Internal  structure  of  Rocks — 
laminar,  fibrous,  spheroidal,  prismatic,  veined, 
cavernous,  amygdaloidal,  aggregate,  granular, 
porphyritic — Texture — Fracture — Hardness — 
Color — Frangibility — Lustre — Trasparency — 
Specific  gravity — Action  of  Acids  .  .126 

LECTURE  V. 

Primary  Rocks.  Granite — Gneiss — Mica  Slate — 
— Argillite — Serpentine — Limestone — Quartz 
Rock — Chlorite  Schist — Talcose  schist — Horn- 
blende Rocks — Actynolite  Schist — Porphyry- 
Syenite — Identity  of  Formations — Isocronism— 
Alternation — Loxodromism — character  of  pri- 
mary soils.  .  .  .  .  146 


CONTENTS  X11I 

LECTURE  VI. 

Transition  rocks — Argillite — Greywacke — Lime- 
stone-—Gypsum— -Porphyry — Syenite — Green- 
stone— Secondary  rocks — Observations  on  their 
formation — Old  Redsandstone — Coal— indica- 
tions of  it — Shale — Limestone— Rock  Salt — Va- 
riegated Sandstone — Shell  Limestone— Lias — 
oolites — Iron  sand — Greensand — Chalk — Ter- 
tiary Formations — of  France — of  England — 
of  America— Alluvial  and  Diluvial — Overlying 
Rocks — conclusion  .  .  .  .199 

SYNOPSES  OF  ROCKS. 

Granite         .                            ...  274 

Gneiss               276 

Mica  slate             279 

Argillite             .                  ...  281 

Serpentine             ...  .         286 

Primary  Limestone            .         .         .  287 

Quartz  rock         ....  290 

Clorite  schist  292 

Talcose  schist      ...  294 

Hornblende  rocks              .         .         .  295 

Actynolite  schist           .         .         .  298 

Old  Redsandstone                       .         .  299 

Coal              301 

Peat  304 


XIV  CONTENTS. 

Shale                    .....  305 

Gypsum    .        .         .         .                 „  307 

Secondary  Limestone           *        ,        .  307 

Sandstones  (superior)                .         .  311 

Clay             314 

Marie                315 

Sand             .         .         .         .         .         .  316 

Alluvia             316 

Superincumbent  or  overlying  rocks  320 

Volcanic  rocks          .  337 

Conglomerates              ....  342 

Tabular  arrangement  of  Rocks  by  Hum- 

boldt 350 

Werner's  Arrangement            ,        .  355 

Macculloch's  do,          ....  356 

List  of  Fossil  organic  remains          »  357 


LECTURE  I. 

Introductory  Remarks — Divisions  of  Natural  His- 
tory— Geological  Theories—*  Stewards  Opinion  of  Theo- 
ries, Fontanette's,  Bailly's —  Theory  of  Burnett, — Pro- 

togcea   of  Leibnitz Woodward — -Hook — Halley — 

Whiston Lazoro   Moro — De   la   Pryme — King — 

Deluc — Guettard —  Lister — Lehman —  Whitehurst 

Kirwan — Buffon — Hutton — Saussure — Pallas — Wer- 
ner. Observations  on  the  Theories  of  Hutton  and 
Werner. Deluge,  traditions  of  it. American  Geo- 
logists.— Striking  Coincidences  between  Sacred  History 
and  Geology. 

While  we  are  prospering  in  Commerce  and  the 
Arts,  it  is  gratifying  to  every  liberal  mind  that 
Science  is  cherished  in  our  country,  and  that  the 
great  cause  of  intellectual  improvement  has  be- 
come one  of  the  most  popular. 

When  the  Sun  of  Science,  towards  the  close  of 
the  1 5th  century,  dawned  on  Europe,  from  the 

dark  cloud,  which,  for  nearly  400  years,  had  en- 
3 


rapt  intellectual  progress,  there  were  but  lour 
classics  in  the  Royal  Library  of  Paris:  France 
and  England  were  in  barbarism;  America  undis- 
covered. 

A  taste  for  polite  literature  was  first  spread  over 
the  west  of  Europe  by  the  fall  of  the  Eastern 
Empire,  and  the  consequent  dispersion  of  the 
Greeks.  It  was  enhanced  by  the  noble  dis- 
covery of  the  Art  of  Printing,  which  secured  to 
itself  the  patronage  afforded  by  the  enlightened 
and  liberal  minds  of  a  succession  of  Popes.  They 
encouraged  learning  and  the  sciences,  and  in  dis- 
seminating them,  gave  full  assurance  of  the  per- 
petuation of  this  valuable  Art,  and  of  the  progres- 
sive improvement  of  human  knowledge.  But 
Philosophy  was  not  courted  with  the  zeal 
paid  to  Literature :  Aristotelian  maxims  contin- 
ued to  be  universally  received  until  the  17th  cen- 
tury, when  Bacon,  Lord  Verulam,  the  profound 
philosopher,  and  most  universal  genius  of  any  age. 
dissipated  the  mist  of  error,  and  threw  a  blaze  of 
light  on  useful  science,  by  which  experiment  and 
observation  were  discovered  to  be  more  convin- 
cing than  system  and  hypothesis. 

In  slightly  adverting,  as  I  have  done,  to  Peri- 
patetic philosophy,  it  is  unnecessary  to  recall  your 


attention  to  the  school  of  Plato,  the  father  of  an- 
cient philosophy ;  or  to  follow  the  division  of  his 
school  by  Zenocrates   and   Aristotle,     However 
delightful  the  task,  we  shall  refrain  from  entering 
and  enjoying  the  Academy  of  the  one,  nor  shall  we 
walk  in  the  delightful  suburban  grove  of  Athens* 
with  the  other.   We  need  not  trace  that  philosophy 
which  was  patronised   by  Julius  Caesar  and  Au- 
gustus ;    which  was  taught  by  Alexander  of  Ana- 
phroedeseus  ;  introduced  among  the  Jews  by  Aris- 
tobolus,  and  among  the  Arabians  by  Al  Mamon. 
To  this  omission  I  am  the  more  reconciled,  since 
a  learned  exposition  of  that  school  has  already 
been  laid  before  you,  in  the  eloquent  discourses  of 
my  colleague,  on  the  history  of  the  philosophy  of 
the  mind.     I  must  be  allowed  to  say,  however,  that 
it  was  that  philosophy,  which  in  the  earliest  ages 
of  Christianity  rendered   itself  obnoxious  to  the 
church,   by   its   doctrine  of  the   eternity  of  the 
world.     Still  it   forced  its  way  within  the  Chris- 
tian pale,  and  re-established  its  reputation  :   and 
from  the  5th  century  the  Aristotelian   philosophy 
rose  or  fell  with  science  in  general,  until  its  incon- 
sistency with  religion  and  true  philosophy  was  ex- 
posed, at  the  period  I  have  mentioned,  by  Bacon, 
the  father  of  experimental  philosophy. — Bacon ! 


16 

unhappy  name  in  the  annals  of  science !  "the 
wisest,  brightest,  meanest  of  mankind," — a  blazing 
beacon,  to  show  us  the  fallacy  of  man  in  founding 
his  reputation  on  literary  or  scientific  attainments, 
not  supported  by  moral  principle — to  show  us  that 
genius  and  talents,  when  not  connected  with  vir- 
tue, "  but  lead  to  bewilder  and  dazzle  the  blind." 

By  the  happy  constitution  of  society  in  this 
country,  few  are  enabled  to  devote  themselves  ex- 
clusively to  the  study  of  nature.  As  in  politics 
and  in  morals,  so  in  literature  and  in  science,  we 
form  individually  but  separate  links,  which,  when 
united,  become  one  strong  chain.  Like  the  fed- 
eral government,  which  is  composed  of,  and  up- 
held by,  our  different  states,  so  the  republic  of 
literature  must  depend  on  the  combined  exertions 
of  many. 

Our  local  position,  our  government,  our  freedom 
of  religion,  are  all  peculiar  to  us  ;  but  not  so  our 
literature  ;  that  we  possess  in  common  with  Eu- 
rope, nay,  with  Britain  only.  With  different  laws, 
opposite  governments,  and  in  different  hemis- 
pheres, America  and  Britain  enjoy,  in  the  same 
language,  a  common  fund  of  literature,  to  which 
they  both  add  according  to  ability,  and  whence 
they  both  draw  according  to  inclination.  Accord- 


17 

ingly,  the  Naturalists  of  Europe  send  us  frequent 
and  important  acquisitions  in  the  sciences,  and 
we  endeavour  to  repay  the  obligation  by  our  re- 
searches on  this  side  of  the  Atlantic. 

It  is  within  the  recollection  of  many  of  those, 
whom,  by  the  partiality  of  my  Associates,  I  have 
now  the  honor  of  addressing,  when  the  terms  of 
Science  were  scarcely  understood  among  us. 
Knowledge  is  not  stationary :  its  progress  is  rapid, 
or  it  retrogrades.  It  may  here  be  emphatically  said, 
that  "  he  who  is  not  with  us,  is  against  us."  Mental 
exertion  and  mental  improvement  have  kept  pace 
with  each  other,  until  the  present  state  of  Science 
and  Literature  was  perfected. 

THE  interior  of  our  planet  is  occupied  by  shape- 
less and  numerous  masses,  lying  on  each  other  in 
a  certain  order.  To  discover  their  nature,  arrange- 
ment, and  relations,  is  the  part  of  GEOLOGY. 

The  various  substances  scattered  through  these 
beds,  having  in  common  with  their  matrices,  cer- 
tain laws  of  their  own,  peculiar  to  each  species, 
it  is  the  business  of  MINERALOGY  to  collect  and  de- 
scribe. They  are  bodies  without  motion,  power 
or  life. 


18 

The  vegitable  carpet  of  nature,  which  covers 
our  planet,  "  the  grass,  and  herb  yielding  seed  after 
his  kind,  and  the  tree  yielding  fruit,  whose  seed 
was  in  itself,  after  his  kind" — organised  bodies, 
with  life,  but  no  sensation,  belong  to  the  depart- 
ment of  BOTANY. 

These  three  departments,  it  will  be  seen,  de- 
rive much  assistance  from  CHEMISTRY,  which  treats 
of  those  events  or  changes  in  natural  bodies,  which 
are  not  accompanied  by  sensible  motions. 

Man,  made  in  the  image  of  his  Creator,  and  to 
whom  u  He  gave  dominion  over  the  fish  of  the  sea. 
the  fowl  of  the  air,  and  over  the  cattle,  over  every 
living  thing  that  moveth  upon  earth,  over  every 
herb,  and  every  tree — man,  with  all  the  subordi- 
nate and^less  perfect  animals,  is  made  the  province 
of  ZOOLOGY. 

It  is  my  lot  to  treat  of  GEOLOGY — and  I  propose 
at  the  present  time  to  give  a  rapid  sketch  of  the 
rise  and  progress  of  this  Science,  and  the  various 
Theories  that  have  been  published  in  illustration 
of  it.  This  I  am  the  more  emboldened  to  do,  be- 
cause, as  Stewart  says,  it  is  not  from  his  own  erro- 


19 

neous  hypothesis  alone  that  the  philosopher  is  as. 
sisted  in  the  investigation  of  truth.  Similar  lights 
are  often  to  be  collected  from  the  errors  of  his  pre- 
decessors :  arid  hence  it  is,  that  accurate  histories 
of  the  different  Sciences  may  be  justly  ranked 
among  the  most  efficient  means  of  accellerating 
their  future  advacement. 

It  was  from  a  view  of  the  endless  and  hopeless 
wanderings  of  preceding  enquirers,  that  Bacon  in- 
terred the  necessity  of  avoiding  every  beaten  track : 
and  it  was  this  which  encouraged  him— -with  a  con- 
fidence in  his  own  powers  amply  justified  by  the 
event — to  explore,  and  to  open  a  new  path  to.  the 

mysteries  of  nature. 

Inveniam  viam,  aut  faciam. 

There  is  no  subject,  says  Fontenelle,  on  which  - 
men  ever  come  to  a  reasonable  opinion,  till  they, 
have  once  exhausted  all  the  absurd  views  it  is* 
possible  to  take  of  it.  What  follies,  he  adds,* 
should  we  riot  be  repeating  at  this  day,  if  we  had 
not  been  anticipated  in  so  many  of  them  by  the^ 
ancient  philosophers. 

Those  systems,  therefore,  which  are  false,  are  by 
no  means  to  be  regarded  as  totally  useless.  That 
of  Ptolemy,  as  Bailly  observes,  is  founded  on  a 
prejudice  so  natural  and  so  unavoidable,  that  it. 


20 

may  be  considered  as  a  necessary  step  in  the  pro- 
gress of  astronomical  Science  :  and  if  it  had  not 
been  proposed  in  ancient  times,  it  would  infallibly 
have  preceded  among  the  moderns,  the  system 
of  Copernicus,  and  retarded  the  period  of  its  dis- 
covery. 

Should  any  one  say  that,  after  all,  our  theories 
are  but  hypothesis,  I  would  beg  you  to  call  to 
mind,  that  it  was  by  the  happy  hypothesis  of  a  ring 
encircling  the  body  of  Saturn,  that  Huyghens  ac- 
counted in  a  simple  and  satisfactory  manner  for  all 
those  appearances,  which  for  years  had  puzzled 
all  tihe  astronomers  of  the  world.  Of  the  accuracy 
of  this  hypothesis  no  reasonable  doubt  can  be  en- 
tertained, when  it  not  only  explains  all  known  phe- 
nomena, but  enables  the  astronomer  to  predict 
with  accuracy  those  which  are  afterwards  to  be 
observed. 

The  earliest  published  theory  of  the  earth  with 
.  which  we  are  acquainted  is  that  of  Burnett.* 
r:^<.  He  supposed  that  the  primeval  earth  was  a  fluid 

*  mass,  composed  of  heterogeneous  materials,  the 
'  heaviest  of  which   descended  to  the  centre,   and 

•  there  formed  a  hard  and  solid  body.     Around  this 

*  "  Telluris  Theoria  Sacra."     London  1680, 


21 

body  was  collected  the  water:  and  all  the  lighter* 
fluids,   the  air  particularly,   ascended   above  the< 
water,    and   encompassed   the  whole.     Between , 
these  orbs  of  water   and   air  was  an  oily  matter, 
upon  which  the  impure  earthy  particles,  blended 
with  the  air,  descended,  and  uniting  with  it,  form- 
ed the  crust  of  the  earth,  which  became  habitable, 
and  was  the  abode  of  men  and  annimals.     In  this< 
state,  as  its  equator  coincided  with  the  plane  of  the- 
ecliptic,  there  was  no  variation  of  season — *  and 
one  unbounded  spring  encircled  all." 

The  surface  he  supposed  to  be  smooth  and  uni- 
form, without  mountains,  seas,   or  inequalities —  > 
nor  did  it  vary  at  all  for  1 6   centuries,  when    the  « 
heat  of  the  sun  dried   the  crust,  and  caused  it  to 
crack  into  fissures  or  crevices,  which  eventually 
deepened  and  penetrated  through  it     These  fis-  • 
sures  enlarged   and  the   enclosed  waters  gushed  • 
out  with  much  violence,  and  in  such  quantities,  as  * 
to  cover  the  dry  land,  and   occasion   the  general f 
deluge.     The  water  at  length  retired  into  cavities, , 
and  as  these  became  filled,  the  earth  appeared  in 
its  most  elevated   parts,  and  formed   mountains, , 
while  the  lower  parts  remained  covered  by  water, . 
and  formed  vallies,  oceans,  &c. 
4 


22 

. 

•  <     The  beauty  of  language  in  which  Burnett  cloth- 

<  ed  his  theory  enabled  him  to  throw  a  kind  of  spien- 

*  dour  over  his  erroneous  ideas,  which  forced  them 
.for  a  time  into  general   acceptance.     It  has  been 

-  asserted,  I  know  not  upon  what  authority,  that  this 
>  theory  had  been  previously  published  by  Francis- 

•  co  Patrizio,   a  professor  at  Rome,  in  a  dialogue 
called  "  II  Lamberto."     It  is  generally  viewed  as 

•  an  elegant  Romance ;  the  product  of  mere  imagi- 
nation, unsupported  by  any  observed  phenomena. 

?      About  the  same  period  the  celebrated  Leibnit/ 

*  published  his  4i  Protogoea,"  in  which  he  holds  that 
'  the  earth  and  all  planets  were  originally  fixed  and 

luminous  stars,  which  for  ages  had  blazed  in  the 

firmament,    until  the  combustible   matter  was  ex- 

»  hausted,  when  they  lost  their  brilliancy,  and  became 

»  opaque  bodies.     The  fire,  by  fusing  the   earthy 

<  matter,  vitrified  it,  so  that   the  base  of  all  things 
belonging  to  the  earth  is  glass,  of  which  sand  and 
gravel   are   fragments.     The   other  earths  are  a 

*  combination  of  sand  with  water  and  salts.     When 

•  this   crust  cooled,  the  aqueous  particles,  which 
•>  had  arisen  afe   vapour,  were  condensed  and  pre- 

*  cipitated,   forming  the   ocean.      These    at  first 
» covered  all  the  earth,   and  the  shells  and  other 

•  marine  products  are  proofs  of  the  fact. 


23 

Woodward  next  appears  on  the  list  of  theorists.*, 
He  observed  several  phenomena  with  attention, 
but  was  only  partial  in  his  observations.  He  notic- 
ed marine  exuviae,  and  supposed  them  left  on  land 
by  the  subsidence  of  the  ocean.  That  while  the 
waters  of  the  deluge  covered  the  earth,  all  solid 
substances  were  held  by  them  in  a  state  of  solu- 
tion. That  eventually  a  precipitation  of  all  mat- 
ters occurred  in  the  order  of  their  specific  gravity  i 
— the  heaviest  first,  and  the  rest  in  order.  That 
consequently  these  strata  were  all  parallel  and 
spherical,  and  encompassed  entirely  by  the  great 
ocean.  That  in  the  course  of  time  some  power- 
ful internal  agent  broke  these  strata  universally, 
and  changed  their  relative  positions,  elevating 
some  and  depressing  others — thus  producing 
mountains  and  valleys  : — in  fine  forming  the  earth 
as  it  now  exists. 

It  is  not  necessary,  in  the  present  state  of  this 
science,  to  urge  arguments  against  this  or  the  pre-  > 
ceding  theory.     Suffice   it  to  say,  that  the   mere 
existence  of  beds  of  light  substances  placed  be- 
neath many  of  greater  specific  gravity  is  at  once  an 

i 
objection  that  cannot  be  removed. 


*  Essay  towards  the  Natural  History  of  the  Earth  and  terres- 
tial  bodies  by  John  Woodward  M.  D.     London  1702, 


24 

The  internal  agent  alluded  to  by  Woodward 
was  probably  the  same  mentioned  by  Dr.  Hook, 
who  in  his  "  Discourse  on  Earthquakes,"  publish- 
ed in  1688,  assumes  that  the  bottom  of  the  sea 
had  been  elevated  by  these  tremendous  convul- 
sions of  nature,  caused  by  subterranean  fires  ;  and 
he  thus  accounts  for  the  existence  of  shells  on  the 
summits  of  mountains. 

Dr.  Halley*  ascribes  the  deluge  to  the  shock  of 

*  a  comet,  or  some   transient  body,  by   which   the 

*  polar  and  diurnal  rotation  was  immediately  chan- 

*  ged,  causing  thereby  a  great  agitation  in  the  sea. 
Thus  he  accounts  for  all  the  strange  varieties  of 
position   we   see  on  the  surface  of  the  earth  ;  as 
high  mountains  standing  on  beds  of  shells  that 
were  once  the  bottom  of  the  ocean,  &c.  &c.     It 
may  be  observed  that   so  violent  a  shock  would 
cause  all  fluids  to  run  instantly  to  the  part  where 
such  a  blow  was  given,  and  with  such  a  power  as 
to  carry  along  with  it  the  bottom  of  the  ocean. — 
But   then  the  deluge  must  have   been  produced 
very  rapidly,  and  by  no  means  in  the  gradual  way 
in  which  we  are  taught  to  believe  that  it  happen- 

*  Phil.  Trans.  No.  383, 


25 

ed,  both  by  scripture,  and  the  observance  of  phe- 
nomena. 

Catching  the  idea  of  Halley,  and  blending  with 
it  the  views  of  his  predecessors,  of  Woodward 
more   particularly,  Whiston  erected  his  theory* 
on  mathematical  calculation,  founded   on  his  as- 
sumed data.     He  endeavours  to  show,  that  on  the  • 
first  day  of  the  deluge,  a  comet,  descending  in  the  - 
plane  of  the   ecliptic,  towards  its  perihelion,  pas-- 
sed  just  before  the  earth,  and,  coming  below  the  - 
moon,  caused,  by  its  power  on  the  tides,  the  el-  * 
liptic  figure  of  the   earth  ;  which  broke,  and  the  * 
waters,  issuing  through   the   crevices  or  fissures,  • 
produced  the  deluge,  in  conjunction  with  the  rain  * 
that  descended  from  the  comet  on  its  return. 

At  first,  the  author  advanced  all  this  by  way  of 
hypothesis  only,  but  afterwards  became  persua- 
ded of  the  truth  of  a  conjecture,  for  which  there  is 
not  the  least  semblance  of  foundation. 

.—«—»- 

In  1 740,  Lazoro  Moro,  an  Italian,  is  said  to  have  • 
brought  forward  the  idea,  that  not  only  mountains, 
but  the  whole  earth  was  raised  from  the  bottom 

*  «  New  Theory  of  the  Earth."     London  1708. 


!  i 

26 

of  the  ocean  by  the  power  ot  combustion,  that 
commenced  soon  after  the  creation.  That  the 
portions  of  earth  which  now  exhibit  no  marine 
shells,  were  elevated  before  the  fish  had  stocked 
the  ocean;  but  that  afterwards  shells  and  fish 
were  thrown  up,  and  deposited  in  strata  along 
with  the  soil.  This  theory  has  been  adopted  at  a 
later  period. 

De  la  Pryme*  supposes  that  the  Antideluvian 
world  had,  besides  mountains,  rivers,  &c.  an  ex- 
ternal sea,  and  that  the  falling  in  of  immense  in- 
ternal caverns,  accompanied  by  earthquakes, 
swallowed  up  most  or  all  of  it,  leaving  the  seas 
only  visible.  From  the  bottom  of  this  sea  arose 
our  present  earth,  in  the  same  way  that  some 
islands  have  been  swallowed  down,  and  others 
thrust  up  in  their  stead,  even  in  the  present  day. 

There  are  many  valuable  and  interesting  facts 
in  accordance  with  this  theory,  which  has  been 
partially  upheld  by  Mr.  King,  at  a  much  later  pe- 
riod.f  He  accounts  for  the  deluge  wholly  by 
subterranean  fires,  which  burst  with  great  vio~ 


*  Phil.  Trans.  No.  266. 
t  Phil.  Trans,  vol.  77. 


27 

Jence  beneath  the  sea,  and  raised  its  bottom,  so 
as  to  throw  its  waters  over  the  land,  where  they 
have  since  remained ;  so  th?*t  the  dry  land  and 
ocean  changed  places,  what  was  covered  by  the 
ocean  becoming  dry,  and  the  waters  resting  on 
the  land. 

We  can  scarcely  believe,  however,  that  the  for- 
mer world  was  completely  destroyed,  as  is  suppo- 
sed by  M.  Deluc,  who  enlarged  on  this  hypothe- 
sis, since  we  are  told  that  Moses  took  the  appear- 
ance of  an  olive  branch  to  be  a  sign  of  the  dimi- 
nution of  the  flood.  This  could  not  have  been 
supposed  to  be  a  submarine  production  ;  nor  are 
we  at  liberty  to  suppose  it  the  produce  of  an  isl- 
and that  had  escaped  the  general  inundation. 

in  1746  Guettard  first  complied  with  the  wishes  - 
of  Lister,  who,  in  1 684,  recommended  the  adop-  • 
tion  of  geological  maps.  He  was  one  of  the  first  • 
writers  who  seems  to  have  forsaken  cosmogony,- 
and  applied  himself  to  geological  enquiries.  He « 
possessed,  for  that  period,  much  important  infor- » 
mation,  which  led  him  to  pretty  correct  conclu-  * 
sions :  for  instance,  he  formed  3  divisions  of  the  » 
earth's  surface.  The  first  he  called  Schistose, » 
which  embraced  the  primary  rocks  ; — secondly  • 


28 

-f 

1  the  Marls,  which  included  the  secondary,  pretty 
,  generally ;  and  thirdly,  Sand,  coinciding  with  what 

*  is  now  termed  tertiary.     His  views  were  too  ex- 

•  tensive  for  the  state  of  the  science  at  the  time  in 

*  which  he  lived. 
.  \ 

Lehman,  who  directed  his  mind  to  this  subject, 

•  soon  discovered  and  demonstrated  the  distinction 

*  between  primary  and  secondary  rocks,  illustrating 

•  his  ideas  by  the  geology  of  the  Hartz.     Like  the 
peasant  of  Virgil,  who  imagined  his  native  hamlet 
the  miniature  of  imperial  Rome,  Lehman  imagined 
the  Hartz  and  the  Erzeberge  a  miniature  of  the 
world.     It  is  needless  to  say  that  they  were  about 
equally  correct. 

Mr.  Whitehurst  studied  diligently  some  parts  of 
England,  for  many  years,  and  being  a  close  ob- 
server, he  collected  very  many  facts,  whence  he 
proceeded  to  erect  a  theory,*  in  which  the  two 
great  agents  are  expansion  and  gravity :  the  for- 
mer derived  from  internal  fire,  and  the  latter 
from  an  accumulation  of  earthy  particles.  The 
expansive  force  at  last  gaining  the  ascendency, 


*"  Inquiry  into  the  original  state  and  formation  of  the  earth,'* 
1786. 


29 

broke  through  the  superincumbent  mass,  and 
forced  up  the  strata  in  all  directions.  The  globe 
was  afterwards  broken  into  comparative  fragments 
by  the  explosion  of  steam,  and  the  primitive  state 
of  the  earth  completely  changed :  and  even  the 
Alps,  Pyrenneess  and  Andes  thus  brought  from  the 
abyss.  For  the  truth  of  his  opinions  the  author 
refers  to  fossils.  There  is  some  romance,  and 
much  valuable  information  in  his  book. 

Kirwan,  an  Irish  philosopher  of  strong  mind 
and  extensive  erudition,  not  believing  in  the  theo- 
ries of  his  predecessors,  turns  at  once  to  the  ac- 
count of  Moses,  as  the  only  one  consistent  with 
actual  phenomena ;  and  ascribes  the  Deluge  to  a 
supernatural  cause — the  express  intention  of  God 
to  punish  the  crimes  of  mankind.  He  says  the 
deluge  was  a  miraculous  effusion  of  water  from 
the  clouds  and  from  the  great  abyss,  and  which 
was  sufficient  to  cover  the  whole  earth.  This  he 
establishes  by  a  reference  to  the  laws  of  the  New- 
tonian theory.  Having  proved  this  fact,  he  pro- 
ceeds to  state  that  the  deluge  commenced  in  the 
great  southern  ocean,  below  the  equator,  and 
rushed  thence  to  the  northern  hemisphere.*  He 

*  Vide  Trans,  of  Roy.  Ir.  Acad.  vol.  6. 


30 

brings  the  following  arguments  in  support  of  his 
views,  viz. — 

1.  That  the  southern  ocean  is  the  largest  col- 
lection of  water  on  the  globe. 

2.  In  northern  latitudes  we  observe  the  remains 
of  animals  from  the  southern  continents  and  ocean, 
but  in   southern  climates  no  remains  of  northern 
animals  of  land  or  water. 

3.  The  traces  of  a  violent  shock  from  the  south 
are  still  visible  in  many  countries. 

4.  The  shape  of  continents,  all  sharpened  to 
the  south,  where  they  are  washed  by  the  southern 
ocean,   indicate   the  force   of  the  shock,  which 
mountains  only  could  withstand ;  such  as  the  cape 
of  Good  Hope — cape  Comorin — the  south  point 
of  New  Holland  and  Patagonia. 

It  will  be  observed  that  Kirwan  endeavoured 
to  go  by  the  Mosaic  account ;  which,  although 
not  intended,  as  some  writer  remarks,  as  a  geolo- 
gical record,  is  still  upheld  by  the  geology  of  the 
present  day. 

We  do  not  believe,  with  some  authors,  that  it 
indicates  presumption,  to  scan  the  works  of  the 
Almighty, — to  attempt  explanations  of  the  deluge, 
or  any  physical  cause,— nor  to  offer  conjectures 
as  to  the  results.  His  power.was  wonderfully  and 


miraculously  displayed  in  that  awful  catastrophe, 
for  the  completion  of  which  the  operation  of  phy- 
sical causes  seems  to  have  been  directed,  and  the 
laws  of  nature  to  have  been  suspended.  In  study- 
ing the  manner  in  which  these  changes  were 
wrought,  or  their  ultimate  effects,  we  see  no  pre- 
sumption, no  doubt  of  the  omnipotence  of  the 
Ruler,  no  disbelief  in  the  wisdom  of  the  Allwise 
Sovereign. 

As  no  theory  that  had  been  issued  came  clothed 
in  the  beauties  of  language  or  boldness  of  concep 
tion  comparable  to  that  of  M.  Buffon,  so  none  has 
ever  been  so  popular,  for  the  fund  of  information 
it  contains.  The  prominent  points  only  can  be 
hinted  at. 

He  supposes  that  the  Earth  and  other  planets 
formed,  originally,  parts  of  that  glorious  orb, 
whence  we,  at  least,  derive  our  light  and  heat : 
and  to  have  been  detached  by  an  oblique  stroke 
of  a  comet.  These  portions  of  igneous  matter, 
forced  thus  from  the  Sun,  assumed  a  globular 
shape  by  the  attraction  of  cohesion,  and  receded 
to  such  a  distance  as  to  allow  them  to  gain  an 
eliptical  motion  round  the  parent  Sun,  where  they 
are  now  retained  by  the  conjoined  effect  of  cen- 


32 

tripetal  and  centrilugal  forces.  By  the  rotary 
^notion,  and  the  fluidity  of  matter,  the  earth  gra- 
dually became  an  oblate  spheriod.  It  eventually 
^cooled,  and  the  aqueous  atmosphere  condensing 
*by  degrees,  descended  upon  the  surface  in  form 
>of  water.  This  water  deposited  sulpherous,  sa- 
»line,  and  other  matters,  which  entering  into  fis- 
sures, &c.5  formed  metallic  veins  and  minerals : 
*arid  part  resting  on  the  surface,  produced  mould. 
'The  internal  part,  he  says,  were,  and  still  are 

•  vitrified  :  the   upper  surface,  being  pumice  arid 

•  scoriae,  were  acted  on  by  the  water  and  other 

•  agents,  and  produced  clays  and  soil.     In  this  state 
'the  tides  and  the  winds  and  the  heat  of  the  sun 

•  began  to   produce  strong  effects.      The  diurnal 

•  motion  of  the  earth,  arid  the  power  of  the  tides. 
i  elevated  the  waters  around  the  Equator,  and  car- 
•ried  there,  from  higher  latitudes,  great  quantities 

•  of  slime,  sand,  clay,  $*c.,  thus  elevating  the  equa- 
torial, and  depressing  the  polar  regions.     Thus, 
'he  says,  we  observe  the  highest  mountains  within 
-the  tropics,  and  there  the  irregularities  of  surface 
-generally  are  greater  than  at  the  poles.     The  ac- 
tion of  water  in  the  scoriae,  produced  excavations 
»in  some  places,  and  elevations  in   others,  which 
» in  course  of  time  formed  islands  and  continents. 


33 

The  destruction  of  mountains,  and  the  formation  . 
of  new  islands,  with  all  the  various  positions  of- 
strata,  so  unaccountable  by  all  other  theories,  he  • 
endeavours  to  reconcile  by  the  chaotic  confusion  • 
thus  produced. 

The  bottom  of  the  sea,  he  says,  resembles,  in  its 
regularity,  all  the  varieties  of  inequality,  of  hill 
and  dale,  earth  and  rock,  that  we  observe  on  dry 
land.  Its  plants  and  shrubs  have  a  similar  regular 
distribution.  As  we  find  under  the  equator  the 
highest  mountains,  so  there  do  we  find  the 
deepest  seas.  Incontrovertible  facts,  he  thinks, 
prove,  that  as  the  dry  and  habitable  portion  of 
the  earth  has  been  once  for  a  long  period  under 
water,  so  similar  changes  are  now  going  on  at  the 
bottom  of  the  ocean,  which  will  eventually  be- 
come dry  land:  but  not  in  an  immense  period, 
since  the  operation  of  like  causes  do  not  produce 
like  effects  in  the  same  time  now  as  formerly. 

All  continents  and  islands  have  their  mountains  * 
in  the  centre,  dividing  them  longitudinally.  From * 
these  the  rivers  run  perpendicularly  to  the  ocean, « 
in  which  they  empty,  wearing  away  mountains,* 
producing  vallies,  and  making  deposits  at  their- 
mouths,  which  are  carried  into  the  ocean,  to  form* 
new  beds,  new  islands,  and  new  continents  :  and  • 


:M 

•  eventually  to  restore  to  the  dominion   of  ocean 
ithe  realms  which  are  now  beyond  its  waters — and 

whose  rocky  barriers  and  broken  coasts  seem  to 
hold  the  language  of  the  flatterers  of  Canute — 
"  thus  far  shalt  thou  come,  and  no  farther." 

In  noticing  this    theory,  I   must    be    allowed 

•  to  say,  that  it  was  only  about  the  time  of  its  pub- 
lication, that  Geology  first  claimed  the  rank  of  a 
» science.     Before  this  period,  scarcely  an  accurate 
•idea  had  been  formed  on  the  subject.     The  few 

rays  of  light  were  scattered,  until  an  unexpected 

nucleus  attracted  the  wandering  atoms,  and  drew 

'them  together.      The  brilliant  genius  of  Buffon 

'diffused  a  radiance  on  philosophical   enquiries. 

It  wasted  itself  in  unprofitable  theories,  but  threw 

•  a  distant  light  upon  the  practical  enquirer.     This 
;is  the  only  subject  on  which  the  splendid  genius 

of  the  naturalist  shed  no  immediate  light :  smaller 
•stars,  however,  were  rendered  perceptible  by  his 
reflected  rays. 

All  these  theories  are  vague,  and  insufficient  to 
account  for  existing  facts;  besides  that  they  par- 
take too  much  of  the  ancient  cosmogony  for  the 
present  day. 

There  are  but  two  other  theories  of  consequence: 
and  these  we  shall  but  slightly  touch  upon,  intend- 
ing in  the  course  of  our  duties  to  refer  to  them  sepa- 


35 

rately,  and  view  their  opposing  principles.  I  shall 
have  been  anticipated  by  many  of  you  when  I 
mention  that  these  are  the  celebrated  theories  of 
Dr.  Hutton  of  Edinburgh,  and  of  Prof.  Werner  of 
Freyburg. 

Dr.  Hutton  published  his  theory  in  1788. 

He  considers  the  Earth  as  a  mere  machine — 
describes  its  mechanism — and  enumerates  the 
powers  by  which  motion  is  produced,  and  activity 
communicated  to  it.  These  are  the  projectile 
power,  gravitation,  the  influence  of  light,  heat, 
cold,  condensation,  electricity,  and  magnetism. 

Observing  that  a  solid  body  of  land  could  not 
answer  the  purposes  of  an  inhabitable  world  with- 
out a  soil  suited  for  vegitation,  he  says  that  this 
soil  is  formed  merely  by  the  decomposition  of 
the  solid  earth.  The  surface  inhabited  by  man, 
and  covered  by  plants  and  animals  is  made  by 
Nature  to  decay — that  the  interior  constantly  fur- 
nihes  soil  which  is  as  constantly  washed  away  by 
the  continual  action  of  water  running  from  the 
mountains  to  the  ocean :  that  thus  heights  are 
levelled,  fertile  plains  formed  from  the  disintegra- 
tion of  mountains  and  rocks,  and  the  materials 
carried  on  to  the  abyss  of  ocean.  This  soil  is 
constantly  formed  and  removed,  and  thus  the  land 


36 

tending  constantly  to  destruction.  To  counteract 
this  Dr.  H.  supposes  the  constitution  of  the  globe 
to  possess  a  reproductive  operation,  by  which  this 
ruined  and  decayed  world  becomes  again  repair- 
ed ;  and  that  the  apparent  destruction  of  the  earth's 
surface  is  in  fact  the  real  cause  of  its  renovation- 
While  this  change  is  going  on,  new  strata  become 
consolidated  by  internal  heat :  all  solid  land  is 
formed  at  the  bottom  of  the  sea,  and  elevated  by 
fire,  inaccessible  to  be  sure  to  human  observation, 
but  still  existing  and  operating.  Simple  fusion, 
then,  is  considered  as  giving  hardness  and  solidity 
to  the  different  strata  that  have  been  condensed 
by  means  of  it.  According  to  this  Theory  the  se- 
condary and  newer  rocks  were  deposited  at  the 
bottom  of  the  ocean,  in  consequence  of  operations 
similar  to  those  now  in  action,  and  the  primary 
were  formed  beneath,  by  internal  fire.  All  mar- 
bles, limestones,  &c,  are  composed  of  the  calca- 
reous matter  of  marine  animals. 

In  this  theory  there  is  a  happy  union  of  the 
Agency  of  both  fire  and  water  ;  the  one  collecting 
and  depositing,  the  other  consolidating  and  ele- 
vating. 

This  system  is  in  unison  with  many  facts  as  seen 
in  Scotland  where  it  originated.  It  has  been  ably 


37 

supported  by  the  elegant  illustrations  of  Professor 
Play  fair.  That  classic  scholar  could  see  the  ordina- 
ry operations  of  nature  producing  Geological  phe- 
nomena, through  an  infinite  succession  of  ages' 
without  beginning  and  without  end.  The  subject 
has  been  rendered  interesting,  independant  of  its 
author,  by  these  illustrations,  which  are  said  to 
display  advantageously  its  principles,  argue  forci- 
bly in  its  favor,  ingeniously  combat  the  objections^ 
and  apparently  establish  its  own  conclusions. 

This  book  continues  to  be  the  text  book  of  the 
best  English  Geologists. 

It  will  be  remarked  that  this  theory  embraces 
many  of  the  points  held  out  by  the  philosophy  of 
Aristotle,  which,  as  formerly  remarked,  secured 
to  itself,  by  its  doctrine  of  the  eternity  of  the  world, 
the  severest  censures  of  the  Fathers  of  the  cl\ris- 
tian  church. 

It  was  about  this  time  that  Saussure  visited  and 
studied  the  Alps,  whence  he  drew  conclusions  the' 
most  important  to  Geology.  While  he  was  thus 
engaged,  Pallas  was  traversing  the  Russian  em-' 
pire,  and,  with  the  zeal  of  a  master,  accumulating* 
facts  for  the  establishment  of  tjie  science. 

6 


38 

Werner,  a  name  almost  revered  in  Germany,  now 
appeared  on  the  list  of  Geologists.  As  he  pub- 
lished but  little  himself,  his  intrinsic  merits  can 

, 

never  be  properly  estimated.  It  is  to  be  regretted 
that  his  apathy  prevented  him  from  publishing, 
His  antipathy  to  the  mechanical  part  of  writing 
was  so  excessive  as  to  be  amusing.  Nothing 
could  finally  induce  to  write  a  line;  and  to  avoid 
reproaching  himself  with  want  of  politeness,  he 
at  last  would  not  open  the  letters  addressed  to 
him. 

A  certain  author  who  wished  to  consult  many 
philosophers  respecting  a  voluminous  work,  circu- 
lated his  manuscript  and  it  was  lost;  after  a  thousand 
researches,  it  was  disinterred  at  last,  from  among 
an  hundred  others,  in  possession  of  Werner.  When 
the  French  Academy  placed  him  among  its  eight 
foreign  associates,  an  honor  coveted  by  the  most 
illustrious  philosophers  of  Europe,  he  never  opened 
his  letters,  and  became  acquainted  with  his  hon- 
ors through  an  Almanack.  And  to  crown  all,  an 
express  which  his  sister  had  sent.tohim  from  Dres- 
den, waited  two  months,  at  an  inn,  at  his  expense, 
waiting  his  simple  signature  to  some  very  pressing 
family  concerns.  He  had  sent  his  "  System"  to 
fhe  press,  but  could  never  endure  the  fatigue  of 


39 

correcting    the    first   proof  sheet.     We  know  it,  • 
therefore,  only  as  promulgated  by  his  pupils ;  who 
looked  upon  him  as  the  genius  of  his  age,  and 
blindly  worshipped  at  his  feet.     They  supposed 
that  his  ideas  formed  at  once  a  mature  system,  el- 
egant and  perfect,  they  termed  it  geognosie,  and 
inscribed  on  it  the  name  of  Werner.     To  this 
merit  he  was  not  entitled.     He  had  a  strong  mind, 
which  was  divided,  and  gave  its  whole  strength  to ' 
minerals  and  systems.     Method  was   his  hobby. 
He  was  fond  of  dividing  and  classifying,  and  latterly 
bought  books,  not  to  study,  but  to  arrange  them 
in  a  certain  order  in  his  Library,     He  is  said  to 
have  debated  alike  on  the  order  of  his  dinner  table 
and  the  arrangement  of  his   cabinet,   and   even 
traced  the  military  art  by  the   laws  of  geology.' 
^  A  man,"  said  he,  "  who  wishes  to  become  a  great 
General  should  begin  his  education  by  studying 
Oryctognosy  and  Geognosy,  at  Freyburg."  It  waa 
his  love  of  system  and  division  that  induced  him 
to  add  to  the  primary  and  secondary,  the  interme-  • 
diate  transition,  which  has  been  likened  to  the  in- 
creasing of  primary  colors  by  the  addition  of  mix-,  • 
ed  tints.     He, multiplied  divisions,  but  he  did  not' 
strengthen  them.     His  great  error  was  in  suppo- 
sing that  Saxony  and  Bohemia  were  the  world  in 


40 

miniature.  Like  Lehman,  he  supposed  that  what 
he  had  seen  was  all  the  world  afforded :  and  that 
he  had  sufficient  data  in  his  own  country  wrhence  to 
draw  conclusions  as  to  the  universal  structure  of  the 
world.  None  but  his  most  attached  pupils  now 
uphold  his  theories,  which  he  carried  beyond  the 
bounds  of  philosophy.  His  ardent  zeal,  however, 
-  diffused  itself  among  his  adherents,  and  he  may 
justly  be  said  to  have  done  more  than  any  other 
man  for  the  advancement  of  Geology. 

We  have  been  detained,  however,  too  long  by  the 
man,  from  his  works.  He  threw  aside  hypothesis, 
and  drew  his  arguments  from  facts. 

His  first  proposition  was  that  the  Earth,  to  some 
depth,  was  originally  fluid — not  from  fusion  by 
heat,  but  from  aqueous  solution.  These  outlines 
are  these  : 

1.  The  surface  of  the  globe  was  originally  soft 
or  fluid,  as  inferred  from   its  present  shape,  and 
geological  phenomena. 

2.  That  for  centuries  after  its  creation  the  earth 
contained  in  its  inner  parts  immense  empty  ca- 
verns, but  sufficiently  solid  to  bear  the  superin- 
cumbent mass. 

3.  The  materials  composing  the  earth  were  at 
one  period  dissolved,  and  held  in  solution  by  wa- 


41 

ter,  whence  they  have  been  consolidated  and  pre- 
cipitated, partly  by  crystalization  and  partly  by 
mechanical  deposition ;  granite  first,  and  the  oth- 
er primary  rocks  in  order,  principally  by  chemical 
precipitation. 

4.  From  this  date   the  waters  rapidly  subsid- 
ed, retiring  into  the  cavities  of  the  earth.'    During 
this  period  other  strata,  the  oldest  secondary,  (or 
transition J  were  deposited. 

5.  The  further  subsidence  of  the  waters  occa- 
sioned, by  mechanical  action,  a  partial  disintegra- 
tion, which  furnished  materials  to  unite  with  those 
still  held  in  solution,  which  were  then  precipitated 
and  formed  the  secondary  horrizontal  beds,  abun- 
dant in  organic  remains. 

6.  During  the  gradual  diminution  of  the  waters, 
and  the  consequent  hardening  of  the  strata,  rent? 
and  crevices  were  formed,  into  which  the  waters 
entered,  still  holding  in  solution  metals,  &c.  &e. 
whence  arise  metallic  veins  and  beds  of  metals. 

7.  That  volcanoes,  and  depositions  from  water 
are  still  producing  changes  on  the  earth's  surface. 

From  the  time  of  Pallas,  Saussure,  Button  and 
Werner,  the  new  science,  which  had  lately  arisen 
under  the  proud  tittle  of  the  theory  of  the  earth- 
attracted  the  notice,  it  merited.  Celebrated  men 


42 

became  its  pupils,  and  we  find  Humboldt,  Cuvier, 
Daubuisson,  Brongniart,  Van  Buch,  Brochant, 
Brocchi  arid  Maclure,  with  many  others,  giving 
their  time  to  perfecting  it :  each  adding  his  obser- 
vations to  the  scale  of  one  of  the  great  masters, 
whence  have  been  derived  the  absurd  titles  of 
Wernerian  and  Huttonian,  or  Neptunian  and 'Plu- 
tonic Theories.  The  one  attributing  most  geologi- 
cal phenomena  to  itfgeRious,  the  other  to  aqueous 
origin.  Both  are  imperfect.  Future  observations 
will  add  valuable  facts,  and  perhaps  accumulated 
evidence  will  weigh  in  favour  of  the  aqueous  ori- 
gin of  most  rocks. 

Whatever  may  appear  from  a  transcient  glance, 
a  complete  examination  of  the  opposing  theories 
cannot  leave  the  mind  biassed  much  in  favour  of 
either.  To  the  Huttonian  theory,  says  Dr.  Murray, 
its  most  violent  opponent,  belongs  the  praise  of 
novelty,  boldness  of  conception,  and  extent  of 
views.  Its  author  has  aspired  not  merely  to  ac- 
count for  the  present  appearances  of  the  earth,  but 
to  trace  a  system,  in  which  the  formation  of  suc- 
cessive worlds  is  developed :  he  has  sought  to  ex- 
tend that  order  and  arrangement,  that  principle  ot 
balance  and  restoration,  observed  in  all  the  de- 


43 

partments  of  nature,  to  the  constitution  of  the  globe 
itself,  and  he  has  succeeded  in  drawing  an  outline 
which  gratifies  the  imagination  with  the  semblance 
of  grandeur  and  design. 

An  enumeration  of  the  arguments  in  favour  of 
this  theory  cannot  be  necessary  to  you.     Suffice  it 
to  acknowledge  that  the  relative  position  of  mine- v 
ral  masses,  their  constituent  parts,  and  the  peculi-' 
arity  of  fossils  render  iriadmissable  the  idea  of  a  * 
central  fire,  existing  without  an  assignable  causef ' 
from  eternity,  and  producing  effects  by  no  means' 
commensurate  with  its  power.     We  are  not  how-  ' 
ever  to  underate  the  agency  of  subterranean  com- 
bustion :     The  known   existence    of    nearly  two 
hundred  volcanic   openings   is  sufficient  proof  of 
the  extent  of  internal  fires  :  and  the  vast  distance  at 
which  the  shocks  they  occasion  have  been  sensibly 
felt,  give  some  idea  of  the  extent  of  their  force, 
which  even  an  intervening  ocean  cannot  restrain. 

The  opposing  theory,  to  which  the  name  of' 
Werner  has  been  improperly  attached,  forms  a. 
simple  contrast  to'improbable  hypothesis.  That1 
the  surface  of  the  earth  has  been  arranged  by 
water,  is  proved  by  a  knowledge  of  geological  facts, » 
In  appealing  to  proofs  from  induction,  we  find  ac-« 
tual  phenomena  in  accordance  with  principles.. 


44 

•  Perfection  is  not  attainable  in  all  things :  while 

any  science  therefore  remains  in  a  state  of  imper- 

•fection,  deficiencies  must  be  discovered  in  the  ap- 

,  plication  of  principles  established  by  induction 

only.     Such  is  the  case  with  this  theory,  yet  it  of- 

'fers  no  inconsistencies,  contradicts  no   facts.     It 

i  is  a  series  of  inductions,  more  or  less  perfect,  re- 

1  ferred  to   a  common  principle,   and  occasionally 

->  connected  by  a  moderate  and  rational  hypothesis. 

/  It  will  have  been  noticed  by  all  of  you  that  no 
attempt  has  been  made  to  explain  the  present  ap- 
pearances of  the  earth's  surface  without  allusion  to 
a  period  when  it  was  inundated.  No  theorist  has 
advanced  an  opinion  in  which  such  an  event  does 
not  form  one  of  the  most  prominent  features.  It 
becomes  necessary,  therefore,  for  one  moment,  to 
f  turn  our  attention  to  that  epoch,  one  of  the  most 
remarkable  in  chronology. 

Previous  to  the  general  deluge,  we  find  by  sacred 
and  profane  history,  that  there  were  several  great 
floods :  of  which  that  happening  in  Greece,  during 
the  reign  of  Deucalion,  is  one  of  the  most  conspi- 
•  cuous.  It  is  said  to  have  occurred  1 529  years  B. 
C. — being  the  third  year  before  the  Israelites  left 
Egypt — (or  1503  according  to  Blairs  chronology.) 

is  flood  inundated  all  Thessally. 


45 

296  years  before  this  flood,  viz.  1020  years'toefore  * 
the  1st  Olympiad,  and  1796  years  B.  d — occurr-  - 
ed  the  deluge  of  Ogyges,  which  ravaged  Attica. 

These  floods  have  occasionally  been  confound- 
ed with  that  of  Noah. 

There  are  other  floods  on  record,  which  may  be 
barely  named — The  deluge  in  Syria  which  in  1095 
A.  D.  drowned  vast  numbers  of  people — that  which' 
in  1164  deluged  Friesland— and  that  which  1218^ 
deluged  the  same  country  and  destroyed  100.000* 
men. 

The  Netherlands  and  Brabant  have  been  seve-  > 
ral  times  inundated  and  their  whole  surface  mate- » 
rially  changed. 

The  deluge,  however,  to  which  geologists  allude, ) 
is  distinguished  as  the  universal  or  Noah's  flood — 
and  is  recorded  in  scripture  (Gen.  6  and  7th  ch.) 
as  sent  by  way  of  punishment  for  the  vices  and  cor-  j 
ruption  of  that  age. 

The  period  of  its  occurrence  is  stated  by  the ; 
best  chronologers,  to  have  been  1656  years  after! 
the  creation,  or  2348  years  B.  C. — and  4173  from 
the  present  year.     On  the  10th  day  of  the  second; 
month,  which  answers  to  Sunday,  Nov.  30th,  Noah 
and  his  family  entered  the  Ark.    On  Sunday  Dec. 
7 


46 

7th,  the  rain  commenced,  and  continued  for  forty 
days.  On  Wednesday  May  6th  (2348  B.  C.)  the 
ark  rested  on  mount  Arravat.  The  tops  of  the 
mountains  became  visible  on  Sunday,  July  19th, 
and  on  Friday,  Dec.  18th,  Noah  and  family  left  the 
ark,  and  built  an  altar  to  God. 

One  hundred  and  fifty  days  therefore  is  the 
period  it  lasted — and  during  this  time  many  of 
those  changes  took  place  which  it  is  in  some  mea- 
sure our  object  to  account  for. 

It  is  a  remarkable  fact  that  this  event  is  pre- 
served in  the  memory  of  all  nations.  In  our  country, 
as  well  as  in  Africa,  Asia,  and  Europe. 

We  are  indeed  told  that  the  Gentoo  traditions, 

neither  written   nor  oral,  make  any  mention  of  it, 

» and  that  the  Bramins  assert  it  never  took  place  in 

'  Hindoostan.     Were  this  true,  it  would  necessarily 

*  excite   astonishment,   since  traditions  of  it  have 
been  traced  in  every  quarter;  not  only  among  the 

'Romans,  Greeks,  Egyptians,  Babylonians,  Persians 
4  and  Scythians,  but  among  our  own  Iroquois,  among 
the  Mexicans,  Brazilians  and  Persians. 

But  Sir  Win.  Jones  asserts  that  traditions  con- 

*  cerning  a  deluge  do  exist  from  Hisdoostan,  and 
4  that  their  oldest  mythological  works  preserved  an 

*  account  very  similar  to  that  of  Moses. 


47 

It  is  asserted  that  some  traveller,  interrogating 
the  inhabitants  of  Otaheite  as  to  their  origin,  re- 
ceived for  answer,  that  a  long  time  ago,  the  su- 
preme God,  being  angry,  dragged  the  earth  through 
the  sea,  and  their  island  being  broken  off,  was 
alone  preserved. 

I  am  not  here  however,  to  defend  or  uphold  the 
accounts  related  in  the  Bible.  It  is  a  history  how- 
ever, which  does  derive  support  from  Geology. 

Although  no  geological  theory  has  been  broach- 
ed on  this  side  of  the  Atlantic,  it  is  with  much  plea-  • 
sure  that  I  am  enabled  to  turn  our  thoughts  home-  • 
ward,  from  the  splendid  constellation  of  European  < 
science,   and    survey    the   rapid    strides   of  this1 
branch  in  our  own  country.     Twenty  years  ago 
Geology  was  known  here  by  name  only.    It  was 
about  that  period  that  the  late  Dr.  Bruce  returned 
from  Europe  with  a  splendid  collection  of  mine- 
rals.    His  zeal  and  attainments,  with  the  conjoin- 
ed efforts  of  Col.  Gibbs,  gave  an  eclat  tothe  study 
of  mineralogy,  appropriately  termed  the  alpha- 
bet  of  Geology,  which  has   produced   the   most 
beneficial  effects.     It  is  needless  to  enumerate  the 
long  list  of  those  who  have  since  successfully  pro- 
moted the  interests  and  diffused  the  knowledge 
of  mineralogy,  serving  as  the  foundation  of  geology. 


48 

*  It  is  not  more  than  fifteen  years  since  we  had 
vthe  first  intimation  through  the  press,  that  any  oi' 
-our  citizens   had  observed  the  geological  pheno- 
imena  of   our   country.       Dr.   Mitchill   and   Dr. 
tArkerly  were  among  the  foremost  to  enlighten  us 

i  on  the  subject,  in  the  first  purely  scientific  jour- 
•nal  established  in  our  country.*  Since  then,  we 
»have  been  annually  enriched  by  the  exertions  of 
» our  friends.  No  great  standard  work  has  yet 

*  been  given  on  the  geology  of  America ;  but  the 
» partial  labours  of  individuals  will  soon  afford  am- 
•ple  materials  for  filling  up  the  outlines  now  so 
'well  known,  and  which  are  more  distinctly  mark- 
*ed  than  in  any  other  country. 

,  The  observations  attached  to  the  American 
,  edition  of  Cuvier's  theory  of  the  earth,  and  the 
.  numerous  notices  of  the  learned  annotator  in  vari- 

*  ous  periodicals  have  thrown  abroad  mucli  infor- 
»  mation  on  the  formation  of  North  America. 

*  The  Essays  of  the  indefatigable  President  of  the 

*  Academy  of  Natural   Sciences,   at  Philadelphia, 
» have  done   much  to   advance   this  Science,  and 
'many  of  the  members  of  that  highly  respectable 

*  society  are  zealously  engaged  in  the  same  cause. 


erican  Mineralogical  Journal. 


49 

Mr.  Hayden  has  published  a  vast  accumulation " 
of  facts  to  prove  that  the  whole  region  skirting  the 
the  Atlantic  ocean  is  the  result  of  the  operation  of 
Currents.     He  attaches  much  importance  to  this 
region,  and  has  partially  marked  out  the  most  in-' 
teresting  formation   that  we  possess  :    I  mean  the 
Tertiary.     The  author  has  evinced  a  knowledge, 
of  his  subject  which  it  would  be  well  for  those  to 
possess  who  oppose  his  views. 

Dr.  Akerly's  Geology  of  the  Hudson  has  been  » 
long  before  the  public. 

Mr.  Pierce  has  described  part  of  New  Jersey  • 
and  the  Catskill  mountains. 

To  Mr.  Hitchcock  we  owe  a  minute  and  inter-' 
teresting  sketch  of  the  Geology  and  Mineralogy  of1 
the  Connecticut  river. 

The  Exploring  Expedition  sent  by  Government,  • 
under  command  of  Major  Long,  to  the  Rocky 
Mountains,  has  greatly  added  to  our  knowledge  of1 
the  secondary  region  to  the  west  and  north. 

The   gentlemen  engaged   in   establishing    the  • 
boundary  line  under  the  6th  and  7th  articles  of  the 
Treaty  of  Ghent  have  afforded   new  information  • 


50 

« concerning  the  country  about  the  great  Lakes  and 
» to  the  north  west.  Major  Delafi eld,  agent  of  the 
"U.  States,  under  those  articles,  and  Dr.  Bigsby  of 
«the  British  Medical  Staff,  attached  to  the  com- 

•  mission,  have  laid  us  under  many  obligations  by 
their  very  valuable  contributions  to  our  knowledge 

•  *  of  that  interesting  region. 

•  Mr.  Schoolcraft  is  now  engaged  in  the  publica- 
tion of  a  work  from  which  we  may  expect  to  de- 
rive much  valuable   information   relative   to  the 
geological  structure  of  our  western  country. 

.  To  the  Hon.  Maj.  Gen.  Van  Rensselaer,  whose 
enlighted  mind,  and  liberal  views  interest  him  in 

•  all  branches  of  knowledge,  we  owe  Geological  and 
.  Agricultural  Surveys  of  the  district  adjoining  the 
-Erie  Canal  and   of  the  counties  of  Albany  and 
'Rensselaer. 

Individual  observations  on  particular  regions  are 
thus  connecting  links  for  the  formation  of  one 
grand  chain,  which  will  eventually  embrace  all  the 
strata,  beds,  veins,  and  minerals  of  our  continent 

The  bold  outline  of  our  primary  range  of  coun- 
try first  attracted   the  notice   of  our  geologists. 
The  secondary  has  been  explored  in  the  grand 
with  tolerable  accuracy. 

• 


51 

The  alluvial  has  received  a  portion  of  attention ; 
indeed  under  this  term  has  been  included  until  of 
late,  the  vast  tertiary  formation  situate  between 
the  alleganies  and  the  atlantic. 

The  vast  number  of  beautiful  fossils  that  we  are 
constantly  receiving  from  our  secondary  and  ter- 
tiary formations  go  far  towards  proving  that  many 
of  our  rocks  are  precisely  of  similiar  formation  with 
many  of  those  of  Europe,  and  afford  new  proofs  of 
the  value  of  these  remains  as  geological  characters. 

Allow  me,  for  one  moment,  in  concluding  this 
sketch  of  Theories,  to  dra\v  your  attention  to  the 
striking  similarity  of  the  Records  of  Sacred  His- 
tory, and  the  phenomena  of  Geology.  Upon  a 
comparison,  I  think  you  will  coincide  with  me  in 
the  assertion,  that  the  Mosaic  account  of  the  struc- 
ture of  our  globe  is  fully  corroborated  by  the 
evidence  afforded  by  the  Science  with  which  we 
are  now  engaged. 

The  account  in  Genesis  maybe  summed  up  hr 
three  articles. 

1st.  That  God  was  the  original  creator  of  all- 
things. 

2d.  That  at  the  foundation  of  the  globe  we  in-  • 
habit,  the  whole  of  its  materials  were  in  a  state  of- 
chaos  and  confusion. 


52 

3.  That  at  a  period  not  exceeding  5000  years, 
(according  to  both  Septuagint  and  Hebrew  Chroni- 

-  cle)  the  whole  earth  underwent  a  mighty  catastro- 
phe, in  which  it  was  completely  inundated  by  the 

•  immediate  agency  of  the  Deity,  and  all  its  inhabi- 
tants destroyed,  except  the  remnant  miraculously 
-preserved  to  continue  the   species.     If  to  these 

-  great  outlines  of  the  sacred  historian,  we  add  that 
the  materials  of  the  globe  were  in  a  fluid  state  pre- 
vious to  its  organization  and  that  its  organization 
was  gradual,  we  embrace  all  the  important  points 
comprised  in  the  Records — and  all  that  the  most 

•  zealous  believer  in  inspiration  is  bound  to  main- 
tain. 

Let  us  now  look  to  the  phenomena  of  Geology, 
and  see  the  conclusions  drawn  from  their  study 
•and  examination.  These  conclusions,  condensed 
•from  the  observations  of  Cuvier,  the  most  acurate 
-naturalist  of  the  present  day,  may  also  be  com- 
<  prised  under  three  heads. 

.     1st.  That  the  sea  has  atone  period  or  other  not 

•  only  covered  all  our  plains,  but  remained  therefor 
•a  long  time  and  in  a  state  of  tranquility. 

2d.  That  there  has  been  at  least  one  change  in 

*  the  basin  of  the  sea  which  preceded  ours  :  it  has 
'  experienced  at  least  one  revolution. 


53 

3d.  That  the  particular  portions  of  the  earth,  • 
which  the  sea  has  abandoned  by  its  last  retreat,  had  » 
been  laid  dry  once  before,  and  had  at  that  time  pro-  • 
duced  quadrupeds,  birds,  plants,  and  all  kinds  of ' 
terrestial  productions  :  it  had  been  inundated  by , 
the  sea,  which  has  since  retired  from  it,  and  left  it 
to  the  possession  of  its  own  proper  inhabitants. 

Thus  we  see  that  the  accounts  of  Moses,  and 
the  results  attained  by  Geology,  or  the  study  of  the 
structure  of  the  world,  coincide,  and  derive  light 
and  support  from  each  other. 

1.  The  prevalence  of  the  waters  at  the  period 
of  the  Creation  described  by  Moses  : 

2.  The  separation  of  the  land  from  the  water, 
producing  a  revolution  in  the  basin  of  the  sea : 

3.  The  irruption  of  the  sea  over  the  continent, 
are  satisfactory  coincidences  between  the  Sacred 
Historian  and  the  Geologist. 


LECTURE  II. 

Objects  of  Geology — its  utility  to  the  Farmer,  Mi- 
ner, and  Architect.  Position  of  Rocks — division  of 
them  into  classes.  Observations  on  the  Primary  Rocks — 
on  the  Transition — Secondary— Tertiary— and  diluvial. 
Organic  Remains.  Divisions  of  the  Earth's  Surface — 
Bottom  of  the  Sea — Dry  Land — Low  Land — Alpine 
Land.  J\lountain  Groups  and  Chains.  Observations 
on  the  Position  and  Declivities  of  Mountains.  Vatties. 

From  the  view  of  Theories  which  I  have  offered 
ito  you  in  the  last  lecture,  it  will  be  seen  that  Ge- 
|ology  is  the  science  purporting  to  illustrate  the 
Structure,  relative  position,  and  mode  of  formation 
of  the  different  substances  composing  the  crust  of 
the  Earth.     It  aspires  to  record  events  of  that  pe- 
jriod  of  time,   when  not  only  the  Earth,  but  the 
whole  planetary  system  was  uncreated.     It  is  by 
induction  only,  however,  that  we  explain  phenome- 
na, and  assign  causes  to  effects  that  have  operated 
in  former  times,  and  thence  down  to  the  present 
day,  through  a  succession  of  ages. 


.05 

By  induction  is  to  be  understood  that  process, 
by  which,  upon  comparing  a  number  of  cases, 
agreeing  in  some  circumstances,  but  differing  in 
others,  and  all  attended  with  the  same  result,  a  Phi- 
losopher connects,  as  a  general  law  of  Nature,  (he 
event  with  its  physical  cause.—  According  to  Bacon 
"Inductio,  quae  ad  inventionem  et  demonstrationem 
scientiarum  et  artium  erit  utilis,  naturam  separare 
debet,  per  rejectiones  et  exclusiones  debitas,"  &c. 
&c.— Nov.  Org.  Lib.  1,  Aph.  106. 

To  the  admirers  of  Nature's  works,  Geology  of- 
fers new  treasures  of  enjoyment,  arid  viewing  the 
sublime  or  beautiful  scenery  which  surrounds  him, 
he  has  greater  cause  than  ever  for  admiration,  in 
its  powers  of  adaptation  to  the  purposes  of  life  ; 
and  exclaims  with  the  melancholy,  but  pious 
Young — 

An  humble,  pure,  and  heavenly  minded  heart 
Is  here  inspired. 

In  referring  to  the  phenomena  of  Geology,  a 
pure  and  classic  writer  has  observed,  that,  few 
questions  are  more  calculated  to  excite  the  specu- 
lative enquirer,  or  more  fascinating  from  the 
grandeur  and  novelty  of  the  objects  it  brings  be- 
fore the  mind.  Nor  can  it  be  said  to  satisfy  noth- 
ing but  a  vain  curiosity.  The  maxim  is  too  well 
established  by  the  history  of  science  to  require 


56 

proof  or  illustration,  that  the  consequences  which 
may  result  from  any  physical  discovery  can  never 
be  foreseen,  and  that  no  investigation  can  he 
deemed  unprofitable  which  may  add  to  our  know- 
ledge of  nature.  A  perfect  Theory  of  the  Earth, 
were  it  established,  would  undoubtedly  admit  of 
the  most  important  applications,  and  a  succession 
of  Theoretical  discussions  may  not  less  contribute 
to  its  attainment,  than  the  accumulation  of  facts. 
With  these  last  it  is  more  particularly  our  business 
to  be  now  engaged. 

The  utility  of  Geology  is  evinced  by  the  zeal> 
with  which,  in  different  parts  of  the  world,  it  is 
cultivated.  And  independent  of  the  gratification 
we  always  feel  in  being  able  to  lay  open  to  ob- 
servation the  Laws  of  Nature,  that  tend  only  to 
inspire  feelings  of  reverence  and  love  to  the  great 
and  good  Being  whose  wisdom  is  so  conspicuous  to 
all,  it  is  of  the  greatest  practical  importance  to 
the  Miner,  to  the  Farmer,  and  to  the  Architect. 


.-  To  miners,  and  consequently  to  all  those  man- 
r  vifactures  connected  with  the  metals  and  treasures 
v  of  the  earth,  it  offers  the  surest  means  of  success, 
*  by  teaching  in  what  rock  or  position  we  may  ex- 

:  ' 


. 

57 

pect  to  find  mineral  treasures  : — that  some  rocks  * 
never  contain  them : — that  metallic  substances  run  » 
generally  in  veins,  and  are  found  only  in  certain  . 
rocks,  and  in  connection  with  certain  other  sub-  * 
stances.  That  coal,  for  instance,  is  never  found  - 
in  the  primary  rocks,  nor  in  the  tertiary,  nor  in- 
the  alluvial  formations — consequently,  it  is  found  * 
only  the  secondary : — and  a  knowledge  of  this 
class  of  formations  teaches  us,  that  it  is  found  on-  • 
ly  in  the  older  of  its  series  ;  as  with  sandstone, 
shale,  (argillaceous  slate)  marl,  argillaceous  * 
porphyry — argillaceous  iron  ore  ;  and  of  these,  * 
most  commonly  with  sandstone,  shale,  and  pud- " 
dingstone. 

It  teaches  the  agriculturalist  whence  to  procure 
substances  to  benefit  his  land,  and  to  render  it 
fertile  ;  and  leads  him  to  choose  such  portions  of 
soil  as  by  their  composition  and  associations  are  " 
best  fitted  for  his  purpose. 

The  subject  of  Mineral  Manures  has  not  receiv- 
ed in  this  country  the  attention  it  merits.  The 
practical  utility  and  value  of  this  knowledge  has 
been  fully  evinced  in  New-Jersey  :  in  illustration 
of  which  I  may  mention  a  fact,  which  came  par- 
tially within  my  own  observation. 


58 

A  few  years  since,  the  inhabitants  of  a  small 
village  in  Monmouth  county,  finding  that  all  the 
labour  they  could  bestow  upon  their  lands  did 
not  render  them  *  productive,  and  that  they 
could  not  force  "  the  churlish  soil  to  yield  them 
bread,"  resolved  to  desert  the  place  of  their  na- 
tivity, and  seek  a  more  friendly  soil.  The  dis- 
covery of  marie,  however,  having  been  made,  and 
mentioned  to  them,  they  resolved  to  give  it  a  trial, 
and  found  it  to  succeed  to  admiration,  and  far  be- 
yond their  hopes.  Land  that  for  nearly  a  century 
had  been  considered  as  without  value,  was  soon 
converted  into  fertile  fields,  yielding  abundant  and 
valuable  crops.  The  consequence  has  been,  that 
the  same  labour  which  would  scarcely  afford  sub- 
sistence, now  offers  wealth  and  contentment. 
The  lands  of  the  county  are  said  to  be  worth  at 
least  one  million  of  dollars  more  since  the  disco- 
very and  use  of  this  mineral  substance. 

The  useful  operation  of  Draining  Land,  another 
subject  of  vast  importance  to  the  agriculturalist, 
depends  in  a  great  measure  upon  a  proper  know- 
lege  of  the  structure  of  the  Earth,  and  of  the  vari- 
ous strata  of  which  it  is  composed ;  as  well  as  their 
relative  degrees  of  porosity,  or  capability  of  ad- 
mitting or  rejecting  the  passage  of  water  through 


59 

them  :  and  likewise  the  modes  in  which  bodies  of 
water  are  formed,  and  conducted  from  different 
elevations. 

The   same   observations    may  be    applied  to 
Springs,  as  it  is  owing  to  these  chiefly  that  Drain- 
ing becomes  necessary  :  and  as  they  consist  simply 
of  water  gliding  along  between   inclined   strata, 
it  is  evident,  that  a  knowledge  of  these  strata  is 
essential  to  the  detection  of  Springs,  and  their  con- 
version to  useful  and  ornamental  purposes.     Thus 
in  some  situations,  Springs  are  only  found  on  one 
side  of  a  mountain — in  other  eminences  occasion- 
ally on  all  sides  of  them.     In  searching  for  Springs, 
therefore,  is  it  necessary  to  examine  the  strata  of 
the  country.     It  is  only  by  this  knowledge  that  we 
can  explain  the  phenomena,  of  the  different  kinds 
of  Springs: — as  the  perennial,  that  flows  constant- 
ly:  the  temporary,  flowing  only  at  particular  sea- 
sons; the  intermittent,  that  flows  and  stops,  then 
and  stops  flows  again;    the  reciprocating  spring, 
that  rises  and  falls,  or  ebbs  and  flows  at  regular  in- 
tervals— called  also  ebbing  and  flowing  wells ;  of 
oozing  and  weeping  Springs — and  many  others  of 
this  kind. 

To  the  Architect,  and  to  the  citizen  who  em- 
ploys him  for  the  purposes  of  ornament  or  comfort, 


60 

this  study  teaches  truths  that  are  but  too  ol'ten  for- 
gotten. The  want  of  attention  to  this  subject  in  pub- 
lic works,  is  a  matter  always  of  deep  regret.  Monu- 
ments of  Art — monuments  intended  to  commemo- 
rate a  great  or  heroic  action,  should  be  so  con- 
structed as  to  remain  for  ages  the  admiration  of 
mankind :  yet  we  often  find  them  erected  of  per- 
ishable materials,  and  scarcely  surviving  the  artists 
who  constructed  them. 

It  would  not  be  in  place  to  advert  here  to  the 
origin  of  the  use  of  stone  in  architecture  or  in  sta- 
tuary, nor  to  point  out  the  most  appropriate  for 
those  purposes.  These  will  be  hinted  at  in  our 
description  of  Rocks,  should  we  have  time.  I  must 
observe,  however,  that '  in  the  erection  of  both 
public  and  private  buildings  we  are  lamentably  de- 
ficient in  respect  to  beauty,  durability,  or  the  inter- 
est of  prosperity.  We  take  our  materials  because 
they  are  near  at  hand,  because  they  are  cheap, 
and  because  others  take  the  same,  in  preference 
to  searching  out  others,  which  although  at  a  dis- 
tance and  more  expensive,  are  more  durable  and 
much  more  beautiful :  which  has  given  rise  to  the 
observation,  that  the  ancients  built,  in  their  full- 
ness of  heart,  for  posterity ;  but  that  we  are  more 
selfish,  and  build  only  for  ourselves. 


6] 

Such  was  the  care  of  the  ancients  to  procure 
lasting  materials  for  their  public  works,  that  had  it 
not  been  for  the  unrelenting  cupidity,  and  more 
than  gothic  barbarism  of  modern  collectors, — more 
unrelenting  than  the  destroying  tooth  of  time,  or 
the  destruction  of  war, 

To  rive  what  Goth,  and  Turk,  and  Time  had  spared, 
What  envious  Eld  forebore,  and  Tyrants  left  to  stand, 

many  Grecian  and  Roman  temples  would  have  re- 
mained perfect  to  the  present  day,  not  effected  by 
the  war  of  elements  for  more  than  2000  years. 

Scarcely  one  building  in  Europe  or  America,  of 
modern  construction,  at  the  end  of  1000  years 
will  have  one  stone  left  upon  another  stone,  to  de- 
note  the  place  where  it  stood.  And  the  most 
splendid  works  of  modern  architecture  are  even 
now  hastening  to  decay,  from  want  of  attention  to 
this  subject.  The  elegant  chapel  of  Henry  VII. 
near  Westminster  Hall,  in  London,  is  an  illustra- 
tion of  this  sad  truth.  In  the  short  space  of  300 
years,  all  the  beautiful  ornament  with  which  the 
exterior  was  so  lavishly  adorned,  has  crumbled 
away.  I  saw  the  workmen,  a  few  years  since,  in- 
serting new  stones  on  which  the  sculpture  was 
copied,  in  place  of  those  that  were  decayed  ;  but 

from  the  same  want  of  judgment  in  the  choice  &f 
9 


62 

materials,  the  present  casing  will  not  last  longer 
than  the  original. 


In  our  various  excursions  in  the  country,  most, 
if  not  all  of  us,  have  observed,  no  doubt,  that  we 
seldom  travel  far  over  the  same  kind  of  rock ;  but 
that  they  usually  alternate  or  vary. 

The  great  rock  masses  or  beds,  are  very  sel- 
dom exactly  horizontal,  and  still  less  often  do  we 
find  them  perpendicular  :  they  all  have  some  in- 
clination to  the  horizon — thus 


The  angle  with  the  horizon  is  called  the  Dig — and 
the  edge  that  appear  on  the  surface  is  called  the 
Basset,  or  cropping  out.. 

Upon  an  attentive  examination  of  these  strata 
we  perceive  that  their  position,  their  ingredients, 
and  their  associations  vary  materally  from  each 
other ;  that  each  has  certain  peculiarities  of  its  own 
but  that  several  of  them  have  many  laws  in  com- 


63 

mon  with  others,  their  neighbours.  This  has  led 
to  a  division  and  classification  of  rocks,  which  has 
been  variously  altered  and  modified. 

Lehman,  as  before  stated,  first  divided  the  rocks 
into  the  older  or  primitive,  which  contain  no  or- 
ganic remains,  or  petrifactions,  as  they  are  called, 
and  into  the  secondary,  in  which  he  included  all 
other  rocks.  A  very  judicious  division,  for  the 
period  in  which  it  was  made. 

To  these,  as  before  remarked,  Werner  added  the 
Transition,  (or  those  which  contain  only  a  few  or- 
ganic remains)  and  called  those  secondary  rocks 
containing  many  remains  Flcetz,  because  he  thought 
them  horizontal.  His  pupils  again  divided  this 
class — and  made  the  later  rocks  into  a  new  class, 
which  they  called  Newest  Floetz — embracing  many 
that  are  now  termed  Tertiary. 

Another  classification  has  been  lately  proposed 
in  that  excellent  work  "  on  the  Geology  of  Eng- 
and  and  Wales,"  by  Messrs.  Conybeare  and  Phil- 
lips, viz. : — 


64 


Character. 

°roposed  Names. 

Wernerian 
Names. 

Other  Names. 

1.  —  Formations   (chiefly 
of    Sand  and  Clay) 
above  chalk. 

Superior  Order. 

Newest  Flcetz. 

Tertiary  Class. 

2.  —  Comprising 
a.  Chalk, 
b.  Sands  and  Clays, 
beneath,  the  Chalk, 
c.  Calcareous  Free- 
stones (oolites)  & 
Argillaceous  beds. 
a.  New  Red    Sand- 
stone, Conglomer- 
ate and  Magnesian 
Limestone. 

Supermedial 
Order. 

Flcetz. 

Secondary 
Class. 

3.  —  Carboniferous  Rocks 
comprising 
a.   Coal  Measures, 
b.  Carboniferous 
Limestone, 
c.  Old      Red     Sand 
Stone. 

Medial  Order. 

Sometimes  referred    to   the 
preceding,  sometimes    to    the 
succeeding  class  by  writers  of 
these  schools  —  very  often  the 
coal  measures  are   referred  to 
the  former  ;  the  subjacent  lime- 
stones &  sandstones  to  the  latter 

4.  —  Roojing    Slate,    &c. 
&c.  &c. 

Sub  me  dial 
Order. 

Transition 
Class. 

Intermediate 
Class. 

5.—  -Mica  Slate. 
G  neiss  and  Granite. 

Inferior  Order. 

Primitive 
Class. 

Primary 
Class. 

These  divisions  are  the  same  with  those  gene- 
rally recognised  hy  geological  writers,  excepting 
that  the  3d  is  by  some  combined  with  the  second 
—by  others  with  the  fourth,  but  all  geological  anal- 
ogies and  relations  are  grossly  violated  by  the  for- 
mer of  these  methods  ;  and  though  the  latter  is 
less  open  to  objection,  yet  we  shall  best  consult 
that  convenience  to  the  student  which  it  is  the  great 
object  of  all  such  arrangements  to  promote,  by  as- 
signing to  so  important  a  series  a  distinct  place  in 
the  general  system.  Different  authors  have  as- 


65 

signed  different  names  to  these  classes,  from  their 
Theoretical  views :  the  present  terms  are  from  the 
fact  of  their  relative  position.  Regarding  the  Car- 
boniferous as  the  middle  group,  the  term  medial  has 
been  given  to  it,  and  super-medial  to  the  one  next 
above,  and  sub-medial  to  the  one  next  below.  The 
superior  and  inferior  are  applied  to  the  highest  and 
lowest  series. 

The  terms  Primary,  Secondary  and  Tertiary 
are,  in  general,  applicable  to  all  known  countries, 
but  it  does  not  follow  that  they  are  necessarily 
parts  of  the  same  formation,  extending  to  different 
countries  ;  as  independent  formations  are  numer- 
ous and  extensive,  and  occasionally  some  may  be 
wanting.  Thus  in  many  parts  of  our  own  country, 
the  older  secondary  (by  the  pupils  of  Werner  call- 
ed Transition^  is  not  to  be  found  ;  and  even  on  the 
borders  of  the  Alleganies,  can  scarcely  be  defined. 
— Moreover,  we  are  not  prepared  to  allow  in  full 
extent  the  existence  of  universal  formations.  If 
we  once  admit  that  idea,  we  must  acknowledge 
the  trap  of  the  Pallisades  on  the  Hudson  is  the 
same  as  that  of  Edinburgh — and  the  coal  of  Le- 
high  and  Providence  a  part  of  the  bed  of  New 
Castle  or  of  New  Holland. 


66 

The  Primary  or  Primitive  Rocks  are  those  hav- 
ing more  or  less,  a  crystalline  texture :  they  contain 
no  organic  remains — and  form  the  extremes  of  all 
series — that  is  to  say,  they  are  the  highest  as  well 
as   the   lowest  rocks.     They  are  the  lowest  as  all 
others  rest   upon  them — and  are  the  highest,  be- 
cause being  highly  inclined,  and  sometimes  almost 
Vertical,  they  rise  to  day  at  the  summit  of  the 
loftiest  mountains.     Granite,    Gneiss    and    Mica 
Slate  are  the  most  prominent  of  the  primary  class 
— though  they  by  no  means  constitute  the  class  as 
was  formerly  supposed. 

The  Allegany   Mountains  constitute  the  primi- 
tive range  of  the  United  States. 

The  Secondary  Rocks  are  those  lying  on  the 
Primary,  usually  on  their  declevities  or  at  their 
feet.  Their  texture  is  very  seldom  crystalline  ; 
but  more  or  less  granular,  being  in  a  majority  of 
cases,  composed  of  the  fragments  of  the  older 
rocks,  united  by  some  cement.  They  contain  or- 
ganic remains  :  Their  elevation  is  not  so  great  as 
those  of  the  preceding  class. 

Sandstones,  Limestones  and  Slates  are  the  chief 
members  of  this  class.  The  greater  part  of  our 
Western  Country  is  of  these  formations.  The 
great  basin  of  the  Mississippi  may  be  termed 
Secondary. 


67 

The  Tertiary  Class  are  those  of  more  recent 
origin  and  are  all  placed  above  the  chalk.  It  is 
but  a  few  years  that  these  beds  have  been  studied 
— but  they  are  extremely  interesting — their  tex- 
ure  is  earthy  more  or  less — their  position  nearly 
horizontal. — Their  organic  remains  are  many  and 
beautiful.  Until  lately  this  class  has  been  con- 
founded with  Alluvial.  Our  sea-board  from 
Martha's  Vineyard,  including  great  part  of  Long 
Island  and  New-Jersey — indeed  all  that  country 
between  the  Allegany  Mountains  and  the  Ocean 
is  Tertiary. 

Alluvial  beds  are  mostly  local — and  are  de- 
posits of  comparatively  very  recent  formation — in- 
deed these  deposits  are  constantly  going  on,  and 
form  one  of  the  great  changes  now  operating  on 
our  planet.  They  are  composed  of  finer  particles 
mostly,  though  not  always,  that  are  carried  for- 
ward by  water,  and  deposited  mechanically — nev- 
er perhaps  by  chemical  precipitation.  They  are 
usually  on  plains,  at  the  mouths  of  rivers,  or  at  the 
margin  of  mountainous  ridges.  They  consist  usu- 
ally of  sand,  clay,  loam  and  gravel — and  proceed 
mostly  from  the  disintegration  of  rocks,  by  the  ac- 
tion of  running  water,  or  of  the  atmosphere. — 
When  carried  forward  by  rivers,  and  deposited 


68 

at  their  mouths,  they  form  sub-marine  beds  and 
islands,  and  eventual!}  often  fill  up  lakes  and  har- 
bours. The  sea  casts  up  large  quantities  of  sand, 
&c.  increases  its  shore,  and  is  gradually  forced  to 
retire  before  its  own  offspring.  Girgenti,  the  an- 
cient Agrigentum,  in  Sicily,  was  formerly  a  seaport 
of  great  consequence.  When  I  visited  these  mag- 
nificent ruins,  in  1819,  they  were  more  than  four 
miles  from  the  beach. 

The  extent  and  depth  of  these  deposits  vary, 
and  will  be  spoken  of  more  at  large  when  treating 
of  formations  in  detail. 

I  may  remark,  however,  that  when  connected 
with  mountains  and  large  rivers,  they  often  con- 
tain grains  of  metal,  as  gold,  tin  and  iron,  in  such 
quantities  as  to  render  them  worth  exploring. 
Thus  a  shaft  was  sunk  in  the  harbour  of  Falmouth, 
(Eng.)  50  feet  through  alluvial  which  originated 
in  granite,  and  a  thick  bed  of  from  2  to  10  feet, 
found  at  the  bottom,  composed  of  round  masses  of 
tin,  which  produced  £50,000  stg. 

During  the  reign  of  Queen  Elizabeth  the  allu- 
vial near  the  Lead  Hills  of  Scotland  was  washed 
for  the  purpose  of  finding  grains  of  the  precious 
metals,  and  300  men  were  employed.  The  pro- 
duce is  stated  to  have  been  £100,000  stg. 


69 

We  are  not  to  infer  from  this,  however,  that  the 
gold  found  in  the  sands  of  certain  rivers  has  been 
always  detached  from  rocks  by  the  action  of 
water :  since  the  auriferous  sand  is  frequently  con- 
fined to  a  small  district  of  the  river — nor  is  it  al- 
ways found  near  to  the  mountains — nor  is  it  al- 
ways in  level  countries  :  The  Rhine  furnishes  less 
gold  at  Basle  than  at  Strasburg,  much  farther  from 
the  mountains  whence  it  proceeds  :  and  the  river 
Tessino  deposits  no  auriferous  sand  until  it  has 
passed  the  Lago  Maggiore. 

The  alluvial  sands  of  the  Danube,  the  Rhine, 
the  Rhone,  Tagus  and  other  European  rivers  af- 
ford gold — as  do  the  alluvial  of  many  of  the  rivers 
of  Asia.  The  alluvial  valleys  or  plains  of  Africa 
have  long  been  famed  for  their  gold  dust.  Our 
own  continent  is  rich  in  golden  alluvium — the  gold 
of  Mexico  is  found  chiefly  in  this  soil.  On  the 
coast  of  California  are  1 4  leagues  covered  with 
alluvial  soil,  containing  lumps  of  gold.  The  gold  of 
North  Carolina  is  also  found  in  alluvial  soil.  The 
largest  masses  of  alluvial  gold  have  not  exceeded 
30  Ibs. 

The  diamond,  the  sapphire,  the  ruby  and  the 
hyacinth  have  also  been  carried  down  by  cur- 


10 


70 

rents  and  found  in  alluvium.  Organic  remains  are 
frequent  in  these  deposits. 

Formerly,  as  before  mentioned,  all  Deposits 
were  termed  Alluvial,  including  many  that  are 
Tertiary. 

But  we  must  distinguish  from  these  deposits,  the 
Diluvial,  a  name  given  to  those  deposits  which 
have  been  made  by  an  inundation  that  seems  to 
have  covered  all  rocks,  and  to  have  deposited 
their  debris  indiscriminately,  forming  the  last 
great  geological  change,  which  the  surface  of  our 
Earth  appears  to  have  undergone. 

The  rocks  included  in  these  classes  obey  cer- 
tain laws  in  their  order  of  arrangement ;  and  are 
then  said  to  have  a  conformable  position  as 
seen  in  the  figure,  page  62. 

Occasionally  however  some  rocks  do  not  obey 
these  laws — and  we  find  them  lying  on  others  to 
which  they  bear  no  relation — thus  we  find  basalt 
sometimes  resting  on  sandstone,  as  at  the  Palli- 
sades  on  the  Hudson-— which  are  then  said  to  have 
an  unconformable  position — thus 


71 

Jn  the  secondary  rocks  we  often  find  pebbles,  or 
fragments  of  the  older  rocks,  consolidated  into  a 
mass  by  means  of  some  cement.  These  are  term- 
ed conglomerates  or  pudding  stones,  when  the 
pebbles  are  rounded  by  attrition,  or  breccias 
when  they  are  fractured  and  angular. 

In  these  conglomerates  we  usually  notice  peb- 
bles that  are  broken,  and  have  their  fragments 
near  to  them  :  but  as  such  stones  could  not  have 
been  broken  without  violent  force,  their  position 
clearly  indicates  that  they  have  been  subjected  to 
such  violence  in  or  near  the  spot  where  we  now 
observe  them  :  Some  of  these  broken  stones  do 
not  seem  to  their  parts  near  to  them — thus  indica- 
ting that  whatever  may  have  broken  them,  they 
have  been  brought  here  from  some  other  spot,  or 
else  their  other  parts  have  been  carried  to  some 
other  place. 

Some  of  these  retain  their  angles  so  sharp  as  to 
convince  us  that  they  never  could  have  been  much 
tossed  about — while  others  show  us  their  angles 
and  inequalities  rounded  off  by  friction  in  their 
motions.  The  inference  is,  that,  the  rocks  whence 
these  fragments  were  torn  must  have  been  solid, 
and  exposed  to  violence  before  the  beds  were 
formed  in  which  these  fragments  are  found. — 
When  such  beds  are  not  horizontal  (or  nearly  so) 


72 

we  may  conclude  that  they  are  not  in  the  position  in 
which  they  were  formed — but  have  been  elevated, 
or  depressed,  by  some  convulsion  posterior  to 
their  formation. 

1  have  mentioned  that  organic  remains  have  been 
found  in  some  rocks,  and  not  in  others.  As  in  the 
course  of  our  duties  this  subject  will  often  be 
brought  to  mind,  I  must  be  allowed  to  enlarge  up- 
on it  here,  in  preference  to  calling  off  your  atten- 
tion from  the  rocks,  which  we  shall  describe  as 
containing  these  remains  of  former  continents  and 
oceans. 

When  I  say  that  certain  shells  are  peculiar  to 
certain  beds,  and  that  when  in  France  or  Ameri- 
ca we  find  certain  shells,  and  know  them  at  once 
to  characterise  certain  formations  of  England  or 
Germany,  I  do  not  intend  to  assert  the  universal 
identity  of  Geological  formations  ;  but  to  notice  the 
remarkable  uniformity  of  fossil  conchology  in  cer- 
tain beds. 

The  identity  of  mass  and  of  fossils  was,  more 
than  150  years  ago,  insisted  on  by  Lister  :  but  he 
never  dreamed  of  identity  of  mass,  and  diversity  of 
petrifaction,  or  of  diversity  of  mass  and  indentity  of 
petrifactions  ;  and  yet  he  observed,  that  forma- 
tions which  were  distinct  by  the  geognosy  of  situ- 


73 

ation  and  superposition,  contained  in  the  most  dis-' 
tant  parts  of  the  world,  similar  species. 

Of  the  identity  of  formations,  one  of  the  strong- 
est proof  is  derived  from  zoology,  which  indicates 
the  identity  of  fossils  in  certain  beds.  The  study 
of  these  remains  is  a  small,  but  very  interesting  and 
valuable  portion  of  the  duties  of  the  philosophical 
enquirer. 

To  distinguish  the  geographical  limits  of  extinct 
animals  and  plants — to  recognise  the  genera  and 
species  to  which  they  may  be  referred — to  ascer*- 
tain  their  relations  to  each  other — and  to  the  clas- 
ses, orders,  and  families  of  organised  beings  ; — 
their  numbers,  as  relative  to  the  rocks  in  which 
they  are  found  ; — the  progressive  developement 
of  animal  nature  ; — to  arrange  species  of  different 
continents,  and  classify  them  according  to  zones, 
climates  and  hemispheres  ; — to  point  out  the  dif- 
ferences of  fresh  water  and  marine,  offluviatile  and 
pelagic  shells  ; — to  note  the  identical  species  ac- 
cruing in  the  same  formation  in  different  parts  of 
the  globe,  and  allow  them  their  due  weight  in  the 
determination  of  formations,  belong  to  the  study  of 
Geological  Zoology — a  branch  well  deserving  the 
attention  of  the  philosopher. 

Properly  to  appreciate  this  knowledge,  it  is  on- 
ly necessary  in  our  researches  into  nature,  to  en- 


74 

deavour  to  distinguish  strata  which  bear  a  resem-, 
blance  to  each  other,  by  aid  of  their  fossil 
contents. 

In  a  bed  of  Grignon  (in  France)  there  have  been 
found  8  species  of  patella  and  tellina — 10  of  ve- 
nericardia  and  turritella  ;  12  of  mellania  and  am- 
pullaria  ;  15  of  mitra,  bulimus  arid  cytherea  ;  18 
of  ostrea  and  murex,  25  of  plurostoma,  33  of  fu- 
sus,  60  of  cerithium,  and  in  fine,  upwards  of  500 
different  species  of  bivalves,  besides  many  uni- 
valves, &c.  &c. 

Saussure  asserts*  that  at  Monte  Bolca  there  are 
found  105  different  species  of  fossil  fish,  39  of  which 
are  said  to  come  from  the  Adriatic  sea,  3  from  the 
African,  1 8  from  those  of  South,  and  1 1  from  those 
of  North  America. 

Dolomieu  states,t  as  does  Playfair,f  that  in  every 
coal  mine,  the  fern  of  America  is  blended  with  the 
palm  of  Africa,  and  the  bamboo  of  Asia. 

The  clay  at  the  Isle  of  Sheppey,  abounding  in 
sea  shells,  is  reported  to  yield  upwards  of  700  va- 
rieties of  fossil  fruit. 

i 

*§  1335. 

tJourn.  de  Phys.  vol.  39. 

illlustrations. 


Fresh  water  shells  are  mixed  with  marine  shells 
in  several  places,  as  near  London. 

The  alternations  of  fresh  and  salt  water  pro- 
ductions in  the  Isle  of  Wight,  and  in  the  Basin  of 
Paris  are  well  known. 

At  Mont  Matre  the  gypsum  exhibits  animals  of 
land,  air  and  water.*  The  middle  beds  of  that 
rock  contain  fresh  water  shells,  the  upper  and 
lower  marine  shells.t 

At  Monte  Bolca,  impressions  of  fish  occur  with 
land  plants;  and  at  Monte  Pulgnasco,  the  bones 
of  the  elephant  and  rhinosceros  are  mingled  with 
those  of  cetaceous  animals.^ 

Thus  we  see  that  a  formation  may  contain,  in 
different  strata,  petrifactions  specifically  different, 
but  that  some  of  the  lowest  stratum  may  be  min- 
gled with  the  great  mass  of  species  which  occur 
in  the  superimposed  strata.  When  these  are  not 
only  specifically,  but  generically  distinct,  some 
being  fresh  water,  others  pelagic,  it  has  been 
thought  difficult  to  solve  the  unity  of  the  forma- 
tion. 


*Journ.  de  Phys.  vol.  77,  p.  362. 
|Id.  vol.  77,  p.  365. 

jld.  voL  39,  p.  339— Vol.  66,  p  105— Vol.  69,   p.    81— Vol. 
30,  p.  50. 


76 

A  large  mass  of  marine  shells  may  contain  some 
fluviatile  shells,  or  they  may  alternate  in  beds. 
Brongniart*  and  Beudantf  mention  the  experi- 
ments made  by  the  latter  to  prove  how  many  flu- 
viatile molu  sea  can  accustom  themselves  to  live  in 
the  ocean.  Certain  species  of  palludinse  prefer 
brackish  waters,  and  are  associated  sometimes 
with  pelagic,  sometimes  with  fluviatile  shells. — 
Humboldt  has  seen  crocodiles  on  the  coast  of  Ter- 
ra Firma  advance  far  into  the  sea.J 

Relative  to  the  distribution  of  organic  remains, 
a  fact  has  been  advanced  to  prove  that  there  are 
alternate  beds  of  marie  and  gypsum,  between  two 
marine  formations,  containing  fresh  water  and 
land  productions  in  the  centre,  and  marine  pro- 
ductions above  and  below.  This  is  the  case 
(as  mentioned  before)  with  the  gypsum  at  Mont 
Matre.  These  alternations  and  intermixtures  in 
the  basins  of  Paris  and  the  Isle  of  Wight,  have 
been  attributed  to  alternate  encroachments  and 
retreats  of  the  sea,  and  the  occasional  existence  of 
fresh  water  lakes.  The  variety  of  species  among 
the  petrifactions,  and  the  alternations  of  beds,  are? 


*  Geogr.  Min.  pp.  57,  54,89. 

t  Jour,  de  Phys.  vol.  88,  p.  137,  211. 

+Eq.  Reg.  vol.  1,  p.  535  and  vol.  2,  p.  606 


77 

by  some,  supposed  to  be  not  sufficient  to  sanction 
the  idea  that  each  bed  is  of  a  different  formation, 
or  that  the  beds  are  confused,  and  without  Geo- 
logical position.  It  should  be  observed,  however, 
that  even  Messrs.  Cuvier  and  Brongniart  assign  to 
the  same  formation  some  marine  and  fresh  water 
marles  and  gypsums.  Indeed  they  illustrate  the 
term  Formation  by  this  very  alternation  of  beds. 

A  difference  having  been  noticed  between  fossil 
and  the  existing  Crustacea  and  other  animals,  na-< 
turalists  were  induced  to  examine  more  minutely, 
into  specific  characters  ;  and  the  result  has  been- 
a  conviction  that  organic  remains  have  been  de- 1 
posited  in  successive  generations,  and  in  such  or-  / 
der,  that  those  of  one  bed  bear  a  certain  connect- » 
ion  to  each  other,  and  exhibit  peculiar  distinctive » 
points  from  those  of  earlier  or  of  later  deposit :  and' 
that  the  greater  the  distance  between  the  differ-' 
ent  deposits,  the  greater  the  difference  between » 
the  contained  fossils.     This  deduction,  combatted ' 
at  first  by  the  most  learned,  and  ridiculed  by  the 
novi  homines  of  science,  has  been  found  in  strict 
conformity  with  the  phenomena  exhibited  by  ani- 
mal or  vegitable  fossil  remains  in  different  parts  of 
the  world.     The  idea  is  now  prevalent  in  Europe, 
and  upheld  by  the  most  learned  and  celebrated 

Naturalists,  that  the  successive  generations  of  or- ' 
11 


78 

*  ganised  bodies  that  have   dwelt  on  crust  of 

,  globe,  differ  from  the  present  generations,  in  pro- 
portion as  their  remains  are  farther  from  the  Earth's 
^surface  ;  or,  in  other  words,  in  proportion  as  the 

•  time  in  which  they  existed  is  more  remote  from 
*the  present  day. 

These  successive  generations  are  discovered 
only  in  the  strata  forming  the  crust  of  our  globe, 
which  was  composed  by  different  operations  ;  each 
possessing  distinctive  characters,  drawn  from  the 
nature,  order  and  structure  of  the  rocks,  and  ac- 
companying minerals.  To  distinguish  the  periods 
at  which  these  different  deposits  have  been  made, 
is  one  part  of  Geology — and  this  is  best  and  most 

^  accurately  done,  according  to  M.  Brongniart,  by 
the  study  of  organised  bodies.  Even  should  the 
characters  taken  from  the  nature  of  the  rocks, 
from  the  height  of  the  deposit,  from  the  scooping 
of  vallies,  the  inclination  of  beds,  and  their  strata- 
fication,  be  at  variance  with  that  derived  from  or- 
ganic remains,  he  still  considers  the  latter  as  of 
superior  validity.  He  illustrates  his  opinion  by  a 
notice  of  Calabria,  which  for  40  years  has  suffered 
the  most  dreadful  disturbances  from  earthquakes  : 
horizontal  beds  have  become  vertical  :  entire  de- 

-  posits  have  been  transported  to  a  distance,  and 
have  been  placed  unconformably  (or  hap  hazzard) 


79 

upon  other  deposits ;  and  yet  these  masses  and  de-  i 
posits  are  never  referred  to  different  Geological  * 
periods.  He  fully  acknowledges  the  force  of  char- 
acters drawn  from  the  rocks  themselves,  but  avows » 
a  preference  for  those  drawn  from  the  fossils  they  \ 
contain. 

The  labours  of  Mons.  Brongniart,  in  addition  to 
his  advancement  of  the  study  of  subterranean  con- 
chology,  have  served  to  prove  the  identity  of  some 
formations  in  Europe  with  some  of  our  own  coun- 
try :  thereby  confirming  more  fully  his  opinion,  that 
each  formation  has,  so  to  speak,  its  own  Flora  or 
Fauna,  modified  by  time  and  space. 

Zoology  is  thus  made  to  render  a  service  very 
important  to  its  sister  Science,  by  the  determina- 
tion of  relations  between  the  formations  and  their 
fossil  contents.  Not  only  in  comparing  neighbour- 
ing strata,  but  in  ascertaining  those  of  foreign 
and  distant  countries,  Zoology  and  Botany  are 
themselves  elevated  above  the  mere  inspection  and 
comparison  of  distinctive  characters,  and  now  in- 
vestigate the  whole  of  vegitable  and  animal  organ- 
ization. 

The  degree  of  analogy  or  similarity  between  fos- 
sil and  existing  plants  and  animals  is,  by  this  ex- 
tensive view,  made  of  the  utmost  importance, 
though  it  may  be  somewhat  difficult  to  draw  the 


80 

corresponding  marks  and  characteristics  of  ibssii, 
with  recent  or  living  individuals,  species  and  gen- 
era. This  resemblance,  it  will  be  seen,  leads  to 
deductions  important  to  a  complete  Theory  of  the 
Earth. 

Much  prudence  and  deep  research  are  to  be 
employed  in  the  application  of  our  attainments  in 
Fossil  Zoology  and  Botany :  nor  has  this  escaped 
the  accurate  and  penetrating  mind  of  the  Natural- 
ist who  first  established  the  importance  of  this 
study  :  thereby  coinciding  with  the  views  of  the 
deceased  Werner,  who  never  failed,  in  the  course 
of  his  lectures,  to  fix  the  attention  of  his  pupils  on 
the  relations  that  exist  between  certain  fossils  and 
formations  of  different  ages.* 

"  1  do  not  deny,  says  Mons.  B.  that  much  atten- 
tion and  discretion  are  necessary  to  be  used  in 
such  a  matter.  It  is  requisite  to  distinguish  and 
estimate  even  the  influence  of  horizontal  distances 
and  of  climates  upon  the  specific  differences  :  we 
must  know  to  appreciate  the  apparent,  sometimes 
even  the  real  points  of  resemblance,  which  present 
themselves,  in  formations  which  are  evidently  very 
distinct,  in  certain  species  which  have  had  the 
rare  privilege  of  surviving  the  destruction  of  their 

*Essai  sur  le  Gisement  des  roches. 


81 

-•"Of  ' 

contemporaries,    and    of    remaining   always   the 
same,  in  the  midst  of  all  the  changes  which  have 
taken  place  around  them.     It  is  necessary  to  know, 
and  to  recognise,   the   individuals    wrested  from 
other  deposits  and  transported,  (by  whatever  cau- 
ses) to  new  ones  :  and  to  distinguish   them   from 
those  which  have  lived  in  the  places  and  times 
which  the  species  to  which  they  belong  ought  to 
characterise.      All  these  difficulties  are  to  be  ac- 
knowledged ;  and  we  must  be  on  our  guard  against 
those  causes  of  deception  which  introduce  uncer- 
tainties in  Geology,  such  as  we  meet  in  other  sci- 
ences— and  which  impose  upon  the  Geologist  un- 
remitting attention  and  labour,  to  employ  with  dis- 
cernment the  fossil  and  recent  species  whence  he 
takes  his  characters,  and  to  attach  to  them  the  true 
value  that    belongs    to   them    in  Geological  re- 
searches. 


In  speaking  of  the  Earth's  surface,  we  usually 
divide  it  into  Dry  Land — and  Bottom  of  the  Sea. 

Of  the  Bottom  of  the  Sea — It  was  formerly  sup- 
posed that  fossil  coal  and  other  bituminous  sub- 
stances existed  there  in  such  quantity  as  to  cause 
the  bitterness  of  its  waters — and  Count  Marsigli 
made  many  experiments  to  ascertain  the  truth  of 


82 

the  supposition.  No  experiments,  however,  with 
our  present  means,  can  be  sufficiently  accurate  to 
determine  this  question.  Since  the  true  bottom  may 
be,  and  we  know  often  is  covered  by  fortuitous  mix- 
tures of  various  substances,  so  as  to  prevent  a  plum- 
met from  bringing  up  correct  proofs  of  its  nature. 
Veins  of  bitumen  and  salt  doubtless  continue  the 
same,  arid  in  the  same  order  under  the  sea,  that  we 
find  them  on  the  land;  and  the  same  strata  of 

»  rocks  which  support  hills,  &c.  on  shore,  no  doubt 
serve  in  the  same  way  to  support  the  immense 

,  mass  of  Ocean  water.  It  is  probable  too,  that  the 
metallic  and  other  veins  existing  in  the  Earth,  run 

i  in  the  same  manner  at  the  bottom  of  the  Sea.     The 

,  loose  particles  perhaps  carried  off  to  deep  water, 
and  there  deposited — but  some  of  the  veins  may 
cbe  exposed,  and  probably  yield  that  beautiful  me- 

•  tallic  lustre,  which  we  so  frequently  find  on  sub- 
t  stances  drawn  from  the  depths  of  Ocean. 

}      Subterranean  rivers,  it  is  probable,  make  great 

changes  in  the  bottom  of  the  sea.    We  know  of  the 

existence  of  subterranean  currents,  and  the  effects 

*they  sometimes  produce  on  the  surface  of  the  globe, 

v  such  as  the  falling  in  of  large  portions  of  ground — 

'  and  the  undermining  of  mountains.     In  the  same 

•  way  we  know  of  the  existence  of  submarine  cur- 
» rents,  which  may,  or  may  not  be  occasioned  by  the 


83 

breaking  out  of  rivers  at  the  bottom  of  the  sea,  and  • 
thus  tend  at  the  same  time  to  alter  the  natural  sur-> 
face  at  the  bottom.     In  clear  water,  near  the  shore? 
we  often  see  these  currents,  and  can  draw  up  the 
fresh  water. 

It  is  a  pretty  universal  rule  among  those  of  our 
brethren,  whose  "  home  is  on  the  mountain  wave," 
the  sailors,  that  in  proportion  as  shores  are  rocky, 
high,  and  steep,  so  is  the  depth  of  water  below8 
them:  and  that  low,  level  shores  indicate  shallow 
water.      It  is   generally   acknowledged   that  the* 
deepest  part  of  the  Mediterranean  is  under  the 
height  of  Malta— and  we  know  that  in  approach-  • 
ing  Long  Island,  the  water  is  shallow.     A  know-  • 
ledge  of  the  strata  on  shore,  in  this  way,  may  * 
teach  us  the  materials  forming  the  bottom,  as  it ' 
stretches  under  water  for  some  considerable  dis-  ' 
tance. 

It  may  justly  be  supposed  that  the  inequalities J 
under  water  are  the  same  as  those  above.     Capt.' 
Cook  in  the  Pacific,  tried  sounding,  unsuccessfully, 
with  250  fathoms  of  line.     Capt.  Scoresby  tried 
1200  fathoms  in  the  Arctic  seas,  without  finding 
bottom.     Besides  a  direct  knowledge  of  the  depth* 
of  water  by  the  use  of  the  plumb-line — and  the ' 
inference  drawn  from  the  appearance  of  the  shore, 
we  have  another  criterion — I  mean  the  thermome- ! 


84 

uer,  to  tell  us  when  we  have  shoal  water.  This 
Instrument  shows  a  diminution  of  temperature  in 
&he  water  as  we  approach  land.  I  dwell  particu- 
larly on  this  fact,  as  it  is  owing  to  a  want  of  know- 
ledge of  these  particulars,  that  two  fine  packets 
in  the  Liverpool  line  have  been  lost  within  a  few 
miles  of  our  city,  within  the  last  eight  months. 
Losses  that  may  justly  be  attributable  to  igno- 
rance— I  do  not  say  carelessness — so  sure  an  in- 
dicator is  the  thermometer,  in  the  water,  of  the 
approach  of  land,  particularly  on  the  East  coast 
of  the  United  States.  I  may  refer  for  particulars 
to  an  Essay  on  the  Natural  History  of  the  Ocean, 
published  by  Professor  Silliman,  in  the  5th  vol. 
of  his  American  Journal  of  Science. 

The  coral  fisheries  give  us  occasion  to  discover 

the  existence  of  many  large  submarine  caverns, 

-.which,   from   the  action  of  the  water,   are   more 

liable  to  become  large  and  empty,  by  the  solution 

»  0f  mud  &c.,  than  caverns  are  on  dry  land. 

From  all  these  circumstances,  in  conjunction 
with  others  which  it  would  be  needless  to  enume- 
rate, we  have  reason  to  conclude,  that  the  bottom 
of  the  sea  is  composed  of  and  covered  by  the 
same  substances  as  the  surface  of  dry  land,  viz. 
rocks,  clay,  sand,  &c.  It  is  in  most,  perhaps  in  all 
places  covered  with  an  accidental  coat.  In  deep 


85 

water,  where  the  surface  only  is  agitated,  the  bot- 1 
torn  is  never  disturbed :   from  such   places,  the  i 
plummet  brings  up  pure  white  sand,  or  a  mixture 
of  triturated  shells — or  a  powder  formed  of  the 
fragments  of  coral,  or  parts  of  rocks. 

The  bed  of  ocean  too  has  its  appropriate  shrubs* 
plants,  and  flowers ;  and  no  doubt  the  geographical 
distribution  of  submarine  plants  is  as  nicely  and 
strictly  defined  as  that  of  Alpine  or  other  plants — 
and  many  of  them  are  extremely  beautiful. 

From  the  depths  of  the  sea  we  often  draw  up 
substances  of  the  most  brilliant  colours — scarlet, 
vermiilion,  purple,  blue,  green,  and  snowy  white :  • 
not  superficial  and  transient,  but  in  most  cases* 
real  and  permanent.     Some  marine  substances,  as ' 
coral,  &c.,  do,  however,  exhibit  on  being  first  drawn 
from  the  water,  the  most  superb  and  brilliant  co- 
lours, which  are  evanescent,  and  fade  in  a  moment. 
The  small  quantities  we  find  on  marine  bodies,  as 
we  approach  deep  water,  may  give  us  some  idea 
of  what  we  might  find  in  the  deep  and  unfathom- 
able recesses. 


"  Full  many  a  gem  of  purest  ray  serene, 
The  dark  unfathomed  caves  of  ocean  bear/ 


12 


36 

A  poet  has  beautifully  described  a  submarine 
scene. 

It  was  a  Garden  beyond  all  price, 

Even  yet  it  was  a  place  of  paradise  ; 
For  where  the  mighty  ocean  could  not  spare.. 

There  had  he,  with  his  own  creation, 
Sought  to  repair  his  work  of  devastation! 
And  here  were  coral  bowers, 
And  grots  of  madrepores, 
And  banks  of  sponge,  as  soft  and  fair  to  eye 
As  e'er  was  mossy  bed. 
Here,  too,  were  living  flowers, 
Which,  like  a  bud  compacted, 
Their  purple  cups  contracted, 
And  now  in  open  blossoms  spread, 
Stretched  like  green  anthers  many  a  seeking  head. 

And  arborets  of  jointed  stone  were  there, 
And  plants  of  fibres  fine,  as  silkworm's  thread  : 
Yea,  beautiful  as  mermaid's  golden  hair, 

Upon  the  waves  dispread  : 
Others,  that  like  the  broad  banana  growing, 
Raised  their  long  wrinkled  leaves  of  purple  hue? 

Like  streamers  wide  outflowing. 
And  whatsoe'er  the  depths  of  ocean  hide 
From  human  eyes,  Ladurlad  there  espied, 
Trees  of  the  deep,  and  shrubs  and  fruits  and  flowers, 
As  fair  as  ours. 

A  silver  trunk, 
The  fine  gold  net  work  growing  out 

Loose  from  its  rugged  boughs, 
Tall,  as  the  cedar  of  the  mountain,  here 
Rose  the  gold  branches,  hung  with  emerald  leaves,. 
Blossom'd  with  pearls,  and  rich  with  ruby  fruit. 


87 

Dry  Land  is  divided  into  Highland  and  Lowland. 
By  Lowland  is  meant  an  extensive  country,  flat,  or 
of  inconsiderable  elevation  above  the  sea — compo- 
sed mostly  of  plains,  and  hilly  as  it  approaches  the 
Alpine  district.  The  few  elevations  that  occur  in 
it  are  small,  and  chiefly  in  the  central  part. 

We  have  one  immense  tract  of  Lowland,  tra- 
versed by  the  Mississippi  and  Missouri,  bordering 
east  on  the  Appalachian,  and  west  on  the  Rocky 
Mountains. 

In  South  America  there  is  also  one  extensive 
district  of  low  land,  bordering  on  the  Andes. 

The  principal  Lowland  of  Europe  comprises 
the  Eastern  portion  of  Britain  and  the  northern 
part  of  France,  the  Netherlands  the  north  of  Ger- 
many and  Silesia,  all  Poland,  and  the  north  west 
part  of  the  Rusian  Empire. 

The  central  portion  of  Asia  consists  of  one  great 
Lowland  Tract,  called  the  Steppes. 

The  extent  of  this  division  of  surface  in  Africa 
has  never  been  ascertained. 

Alpine  land  is  composed  of  groups  of  mountains, 
which  are  again  formed  of  mountain  chains,  or  a 
series  of  single  mountains. 

Mountain  groups  are  usually  highest  in  the  mid-' 
die,  and  in  an  Alpine  country  each  takes  a  differ-' 


88 

ent  direction,  being  separated  by  plains  and  val- 
lies,  or  by  hilly  districts.  Each  group  forms  a 
whole,  both  as  to  base  and  acclivity,  partially  in- 
tersected in  many  places,  but  never  to  the  base, 
except  at  the  termination  of  the  chain. 
i  Mountainous  land  is  composed  of  single  moun- 
tains collected  into  chains,  which,  however,  not 
being  united  by  an  Alpine  or  central  chain,  never 
form  groups. 

The  rounded,  undulating  elevations  of  hilly  dis- 
tricts are  much  lower  than  the  preceding,  and 
form  a  gradual  transition  to  Lowland. 

The  summit  of  a  mountain  chain  is  called  its 
ridge,  and  the  concavities  in  a  mountain  group, 
which  usually  run  parallel  to  its  longest  direction, 
vallies. 

High  mountain  groups  are  those  of  an  elevation 
of  7000  feet  and  upwards — as  the  Andes,  Alps? 
Pyrennees,  &c.  Mountains  of  middle  height,  are 
from  4  to  6000  feet  high.  Low  groups  are  from 
700  to  3000  feet  in  height. 

Generally  the  length  of  a  Mountain  Group  is  in 
proportion  to  its  height,  and  to  the  breadth  of  its 
base.  If  the  breadth  and  length  are  nearly  the 
same,  it  is  called  Massive.  If  the  length  is  consider- 
able in  proportion  to  its  base,  we  say  it  is  a  long 
Mountain  ^Group.  Another  distinction  is  derived 


89 

irom  the  form  and  the  connection  of  mountains 
composing  the  group,  as  the  Common,  the  Alpine, 
and  the  Conic  Mountain  Groups. 

With  regard  to  the  diff<  rent  parts  of  a  Mountain, 
we  recognise  the  foot,  acclivity  and  summit.     The 
foot  is  usually  flat,   and  more  or  less  extensive. — 
The  acclivity  is  usually  considered  as  the  steepest ' 
part  of  the  mountain,  and  is  often  almost  a  perpen- 
dicular precipice.      The  more  gradual  and  gentle 
the  ascent  of  a  moutain,  the  more  rich  does  it  gen- • 
erally  prove  in  ores. 

The  summit  varies  in  steepness  and  shape ;  and 
the  latter  is  indicative  of  the  nature  of  the  rock  of 
which  it  is  composed.  Thus  Granite  and  the  Pri- ' 
mary  Rocks  usually  have  sharp  peaks.  The  elder 
Secondary  (or  Transition)  are  rounded  :  Clay  and 
Basalt  present  short  and  obtuse  conical  summits. 

Though  Mountains  are  styled  "  La  Charpente 
et  1'Ossature  du  Globe  Terrestre,''  yet  the  highest 
are  but  mere  specks  in  proportion  to  the  diameter 
of  the  Earth.  Thus  Mount  Blanc,  the  highest  in 
Europe,  is  on  the  surface  of  our  planet,  what  a 
single  line  would  be  on  a  globe  of  2 1  feet  diameter. 

In  speaking  of  Mountains,  I  must  be  allowed  to 
notice  a  Theory^  accounting  for  their  origin  which 
has  lately  been  proposed  by  a  Mons.  Chabrier  in 


90 

a  Dissertation,  not  long  since  published,  on  the 
General  Deluge.  Having  observed  the  immense 
blocks  of  Granite  scatterred  over  the  North  of  Ger- 
many, and  not  being  able  to  trace  them  satisfac- 
torily (for  himself)  to  the  Mountains  of  Sweden  or 
the  Hartz — he  wisely  has  concluded  them  to  be 
Aerolites. — Having  proved  this  to  hi .3  own  satisfac- 
tion— and  having  ascertained  that  mountains  are 
only  heaps  of  rubbish,  he  doubted  if  granite  and  the 
primary  rocks  were  ever  deposited  from  a  sea 
which  nobody  had  ever  seen — and  from  other  sim- 
ilar arguments,  he  asserts,  that  granite  came,  as  it 
now  exists,  from  the  atmosphere,  with  the  accom- 
panying substances.  This  terrible  shower  of 
mountains  arising  from  the  fragments  of  a  planetary 
body  violently  struck  by  a  comet,  rained  at  once 
upon  the  nucleus  of  ours  (which  gives  him  no  con- 
concern)  the  Alps,  Pyrenees  and  Andes  and  the 
Allegany  and  Rocky  Mountains.  The  substances  in 
falling  crushed  the  tufted  forest  and  produced  coal 
by  compression.  The  destroyed  planet  was  that 
which  had  for  its  satellites  the  four  little  moons, 
Ceres,  Pallas,  Vesta  and  Juno,  which  even  now 
irrefragibly  prove  the  former  existence  of  that  un- 
fortunate planet. 

But  even  this  monstrous  shower  of  mountains 
does  not  satisfy  the  gentleman.     It  was  accompa- 


n ' 

med  by  all  the  waters  of  the  planet,  which  falling 
in  torrents  submerged  the  Earth,  and  deluged  the 
inhabitants :  but  the  rain  of  waters  preceded  the 
rain  of  solids  and  mountains,  which  last  came  very 
opportunely  to  confine  the  waters,  in  part,  and 
form  our  continents.  The  fossil  remains  of  trees, 
offish,  and  the  skeleton  of  a  man  found  at  Guada- 
loupe,  are  the  remains  of  the  vegitable  and  animal 
kingdom  of  the  unhappy  planet. 

Mons.  Cha  brier  supposes  too  that  some  of  the  in- 
habitants of  the  unfortunate  planet  escaped  the 
general  wreck,  and  survived  the  fall,  notwithstand- 
ing all  this  hard  usage — and  he  thus  accounts  for 
the  difference  of  races  as  observed  by  naturalists. 
Thus  the  Negroes  and  Malays  are  probably  the 
decendants  of  the  inhabitants  of  the  other  world — 
which  at  one  and  the  same  time  charitably  furnish- 
ed us  with  mountains  and  negroes. 

It  seldom  happens  that  all  sides  of  a  mountain 
have  the  same  acclivity,  which  fact  has  given  rise 
to  various  theories  This  difference  was  long  ago 
observed,  but  it  was  a  Swedish  Naturalist  who  first 
noticed  that  it  was  so  prevalent  as  to  form  a  law. 
His  observation,  however,  related  to  the  extreme 
end  only,  and  not  to  the  flanks  of  mountains.  He 


92 

stated  that  the  steepest  acclivity  always  faced  that 
part  of  the  country   where  the  land  laid  highest. 

Bergman  observed,*  that  the  different  declivi- 
ties of  the  flanks  of  mountains  bear  an  invariable 
relation  to  their  different  aspects.  He  laid  it  down 
as  a  rule,  that  mountains  running  from  north  to 
south  had  always  the  west  flank  the  steepest :  and 
that  those  running  east  and  west  had  always  the 
south  side  the  steepest. — Thus,  he  said,  the  Alps 
are  steeper  on  the  west  and  south  than  on  the  north 
and  east,  and  the  Cordilleras  are  steepest  on  the 
west 

Buffon  also  noticed  this  fact — as  did  Hermann, 
who  brought  as  evidence  the  Swedish  and  Nor- 
wegian Mountains,  the  Alps,  the  Caucassian,  the 
Appenines  and  the  Ouralians.. 

The  Carpathian  Mountains,  those  of  Norway, 
those  on  the  coast  of  Scotland,  the  Welsh  Moun- 
tains, those  separating  Saxony  from  Bohemia,  the 
Hartz,  the  Pyrennees,  and  those  of  Crim  Tartary. 
in  Europe  :  The  Mountains  of  India  and  of  Syria, 
and  the  Cordilleras  are  testimonies  to  the  truth  of 
the  observation. 

I  may  here  say  that  Pallas  and  Forster  account 

for  the  unequal  declevities  of  the  north  and  south 

. 

*Physic   Descript.  of  the  Earth. 


93 

- 

by  the  supposition  of  a  great  flood  from  the 
south,  giving  the  Earth  its  present  form. 

The  celebrated  Kirwan  accounted  for  all  these 
inequalities  by  supposing  a  two  fold  violent  motion 
of  the  water,  by  which  the  globe  was  covered  :  the 
one  from  north  to  south,  the  other  from  east  to  west. 
This  last  being  intercepted  by  such  mountains  as 
run  north  and  south,  the  impulse  of  the  water  was 
checked,  and  the  Earthy  particles  held  in  solution 
by  the  water,  were  deposited  on  the  eastern  side, 
which  thus  became  more  gentle  and  moderate  : 
while  the  west  side  could  receive  no  such  acces- 
sion, and  of  course  remained  rugged  and  steep. — 
The  northern  current  acted  in  a  similar  way,  on 
the  north  side  of  such  mountains  as  running  east 
and  west,  intercepted  its  course. 

It  is  worthy  of  observation,  that  all  considerable 
chains  of  mountains  run  in  a  direction  north  east 
and  south  west.  Our  Alleganies  are  one  proof  of 
this  remark. 

Vallies,  dividing  Mountains  and  furrowing  the 
surface,  deserve  the  attention  of  the  Geologist,  as 
connected  with  those  events  that  have  contributed 
to  produce  the  present  state  of  our  planet. 

We  find  them  commencing  at  great  elevations, 
and  in  their  course  uniting  in  the  most  efficient 

manner  to  collect  and   carry  off  the  water  and 
33 


-i  * 

94 

moisture  into  some  large  stream,  on  its  way  to  the 
Ocean.  They  present  such  appearances  as  would 
naturally  arise  from  water  forming  channels  for  it- 
self in  retiring  from  land.  On  a  very  small  scale, 
this  is  daily  repeated  on  muddy  and  sandy  shores, 
when  the  tide  is  out.  The  present  inequalities  of 
hill  and  vale,  afford  strong  reason  for  the  supposi- 
tion that  it  was  water  that  produced  them.  We 
are  not  however  to  overlook  the  effect  produced 
by  the  violent  convulsions  that  seem  to  have  ele- 
vated and  depressed  strata,  in  so  many  cases.  In 
mountainous  countries  particularly,  vallies  seem  to 
have  owed  their  first  outline  to  the  disruptive  for- 
ces in  action  around  them.  Instead  of  gentle  slopes 
we  find  deep  hollows,  with  almost  perpendicular 
precipices,  forming  the  receptacles  of  mountain 
lakes.  Yet  even  these  vallies  have  been  greatly 
modified  by  water.  In  low  countries,  where  no 
disturbance  of  the  surface  or  strata  exists,  we  must 
refer  vallies  entirely  to  the  effects  of  running  water. 
The  streams  however  that  now  flow  through  vallies 
do  not  seem  to  have  ever  had  sufficient  power  to 
form  the  channels  in  which  we  now  find  them.  An 
eternity  almost  would  be  necessary  in  many 
cases  for  the  present  rivers  to  produce  the 
vallies  through  which  they  now  roll — and  even 
then  there  would  be  physical  impossibilities.  What 


**, 

95 

. 
an  eternity,  ibr  instance,  would  be  necessary  tor 

running  water  to  produce  the  mountain  passage 
of  the  Highlands,  and  wear  down  the  solid  strata 
of  rock  from  the  very  summit  of  the  Dunderberg 
to  the  present  channel  in  which  our  own  noble 
Hudson  winds  its  way  ! 

Vallies,  running  in  the  course  of  the  mountain 
chains  that  bound  them,  are  called  Longitudinal 
vallies,  and  those  dividing  the  mountains  from  each 
other,  and  cutting  the  mountain  chain  across,  are 
named  Transverse  Vallies. 

It  will  not  be  denied  that  vallies  have  been  form- 
ed after  the  consolidation  of  the  strata  through 
which  they  run ; — for  we  find  the  same  strata  of 
rocks  on  either  side  and  in  the  same  order. 


This  is  the  case  in  almost  every  valley — and  it 
will  be  seen  that  they  very  generally  cut  the  strata 
across. 

In  a  few  cases,  however,  vallies  do  occur  be- 
tween different  strata,  running  longitudinally  with 


96 

~> 

them ;  and  then  the  different  sides  of  the  vallies 
are  of  course  of  different  materials. 


The  cause  that  produced  vailies  has,  in  many 
places,  carried  off  the  strata  that  once  covered 
masses  of  rock  which  we  now  find  bare  or  insula- 
ted hills  :  this  disrobing  of  the  rock  has  been 
termed  Denudation. 


*It  is  well  known  that  not  only  Argillite,  but  every  member 
of  the  primary  class  has  been  occasionally  found  in  contact  with 
Granite. 


• 


LECTURE  HI. 

Changes  produced  on  the  Earth's  Surface,  by  the 
formation  of  Peat,  fyc. — of  Coral  Reefs — Volcanoes — 
Observations  on  their  Structure,  frc. — Vesuvius — Etna 
— Sabrina  Island — Earthquakes — those  of  Lisbon  and 
Calabria — Volcanic  Fire — its  Intensity — Situation — 
and  Origin. 

Independent  of  the  changes  that  are  now  con- 
stantly going  on  by  the  partial  agency  of  water,  we 
have  other  causes  acting  more  powerfully  in  alter- 
ing the  present  configuration  of  the  Earth's  sur- 
face. Of  these  I  shall  briefly  notice  but  three — 
viz.  : 

I.  The  formation  of  Peat ,  Bogs,  and  Mosses, 

II.  The  formation  of  Coral  Reefs— and 

HI.  Internal  Heat,  as  manifested  by  Volcanoes 
and  Earthquakes. 

The  change  produced  by  the  ibrmation  of  Peat 
is  partial  and  trivial  compared  with  the  others. 

Mountain  and  Marsh  Peat  are  formed  in  the 
places  whence  their  name  is  derived,  by  the  de- 


98 

composition  of  plants.  In  the  shallow  parts  of 
lakes  are  found  numerous  subaquatic  plants,  which 
in  summer  flower  at  the  surface  and  then  sink  to 
the  bottom.  By  the  annual  death  of  a  portion  of 
these  a  stratum  of  peat  is  formed  at  the  bottom? 
where  this  process  is  constantly  going  on.  The 
death  of  fresh  water  shell  fish,  and  the  deposits  of 
earth  and  sand  brought  into  the  lake  by  streams, 
assist  in  raising  the  bottom  of  the  lake,  and  thus 
prepare  it  for  other  plants  ;  in  like  manner  to 
thrive,  blossom  and  die. 

In  other  cases  no  distinct  bed  of  peat  is  produ- 
ced from  the  subaquatic  plants — but  a  stratum  is 
formed  by  the  decay  of  land  plants,  which  gradual- 
ly extends  into  the  lake  and  finally  occupies  its 
bed.  The  shells,  which  for  centuries  have  been 
deposited  at  the  bottom  of  the  lake  thus  become 
covered  by  peat,  and  are  eventually  consolidated 
into  marl  beds — thus  offering  one  of  the  most  use- 
ful auxilliaries  to  Agriculture. 

By  occasional  floods,  sand,  gravel,  clay  and 
earthy  particles  are  thrown  over  these  thin  strata 
of  peat,  and  destroy  vegitation.  By  many  and  al- 
ternate similar  causes,  a  series  of  beds  of  peat  and 
of  soil  is  produced,  which  eventually,  exhausting 
the  lake,  becomes  a  fertile  field,  instead  of  forming 
a  peat  or  moss  meadow. 


t     V      "    V      *Sr  -"—" 

N^'-v^w^N: 

99 

Different  kinds  of  peat  have  their  peculiar  plants 
entering  into  their  formation. 

Mountain  Peat  is  formed  principally  by  the  fol- 
lowing, viz.  : 


Erica  cmerea, 

vulgaris, 

tetralix, 
Myrica  gale, 
Empetrum  nigrum, 
Tormentilla  erecta, 
Arbutus  uva  ursi, 
Vaccinium  vitis  idaea, 
Juniperus  communis, 

In  the  formation  of  Marsh  Peat,  the  sphagnum 
palustre  is  the  chief  ingredient,  assisted  materially 
however  by  the  following,  viz.  : 


Polytrichum  commune, 
Lycopodium  clavatum, 
Lichen  rangiferinus, 
Nardus  stnctus, 
Scirpus  caespitosus, 
Juncus  squarrosus, 
Many  grasses  of  the  genera, 
Aira,  agrostis,  and  carex. 


Erica  vulgaris, 
tetralix, 
Myrica  gale, 
Vaccinium  oxycoccos, 
Eryophorum  polystachium, 

vaginatum, 
Schoenus  albus,  and  others  of 

this  genus, 

Scirpus  caespitosus,  and  oth- 
ers of  this  genus, 
Pedicularis  palustris, 
sylvatica, 
Orchis  maculata, 
conopsea, 
Aira  aquatica, 

caespitosa, 
Festuca  fluitans, 


Caltha  palustris, 
Hydrocotyle  vulgaris, 
Lysimachia  tenella, 
Menyanthes  trifoliata, 
Ranunculus  flammula, 
Com  arum  palustre, 
Narthecium  ossifragum, 
Pinguicula  vulgaris, 
Drosera  longifolia, 
anglica, 
rotundifolia, 
Triglochin  palustre, 
Phalaris  arundinacea, 
Arundo  phragmates, 
Juncus,  many  species, 
Carex,  many  species. 
Some  of  the  Equiseta. 


Lake  Peat  receives  into  its  composition  the  fol- 
lowing plants. 

Conferva  bullosa,  Arundo  phragmates, 

Lemna  minor,  Subularia  aquatica, 

trisulca,  Lobelia  dortmanna, 


100 


Nymphaea  alba, 
lutea, 
Potamogeton  natans, 

heterophyllum, 
and  others  of  this  genus, 
Chara  vulgaris, 
Hippuris  vulgaris, 
Callitriche  verna, 

autumn  alls, 
Myriophyllum  spicatum, 

verticillatum, 

Ceratophyllum  demersum, 
Utricularia  vulgaris, 

minor, 
Sparganium  natans, 

erectum, 

Ranunculus  aquatilis, 
Hydrocharis  morsus  ranae, 


Scirpus  acicularis, 

lacustris, 

setaceous  and  others, 
Isoetes  lacustris, 
Alisma  pi  ant  ago, 

ranunculoides  and 
others, 

Saggittaria  sagittifolia, 
Butomus  umbellatus, 
Acorus  calamus, 
Phalaris  Arundinacea. 
Poa  aquatica, 
Juncus  conglomerate, 

effusus,  and  others, 
Schoenus  mariscus,  and 

others, 

Menyanthes  triofoliata, 
Comarum  palustre, 
Equiseta  several  species. 


Bogs  and  Mosses  are  also  accumulations  of  veg- 
itable  matter  in  wet  ground — settling  in  successive 
generations  on  itself,  until  its  bulk  rises  considera- 
bly above  the  level  of  its  bed. — The  surface  of  a 
bog  is  always  undulated,  and  terminates  abruptly, 
sometimes  almost  perpendicularly.  The  average 
height  of  the  great  Irish  bogs  is  about  250  feet 
above  high  water  mark  in  Dublin  harbour. 

Quaking  bogs  are  produced  in  wet,  flat  grounds, 
where  springs  abound.  Weeds,  shrubs,  and  trees,  by 
their  decay  and  fall,  assist  in  darning  up  the  stream, 
and  the  water  becoming  stagnant,  the  whole  flat  is 
overflowed.  A  coarse  grass,  which  is  peculiar  to 
these  bogs,  springs  up  in  tufts  :  the  roots  become 
closely  interwoven,  and  in  a  few  seasons  they  grow 


101 

to  a  considerable  height.  The  decay  of  these 
plants  in  winter,  furnishes  soil  for  the  reception  and 
germination  of  the  seeds  The  tops  of  flags  and 
grass  occasionally  become  intermixed  and  consoli- 
dated on  the  surface  of  the  water,  and  increasing 
in  thickness  and  extent,  cover  the  superficies.—- 
This  receives  seeds,  which  grow  and  cover  it  with 
vegitation,  and  becomes  so  strong  as  to  bear  a  man, 
but  still  in  some  places  trembles,  or  quakes* 
whence  the  name  is  derived. 


The  formation  of  coral  reefs  is  daily  producing 
a  change,  more  or  less,  on  that  part  of  our  globe 
at  present  covered  by  water,  but  more  particular- 
ly in  the  Pacific  Ocean.  They  are  the  production 
of  the  combined  labours  of  millions  of  marine 
zoophytes,  usually  termed  the  connecting  link  be- 
tween the  animal  and  vegitable  kingdoms,  but  per- 
haps more  justly  considered  as  that  link  between 
the  animal  and  mineral  kingdoms.  The  never 
ending  industry  of  these  minute  animals,  is  sup- 
posed by  many  naturalists  to  work  changes  in  our 
globe  far  surpassing  even  those  produced  by  the 
fearful  and  powerful  agency  of  subterranean  fire 

by  means  of  Volcanoes  and  Earthquakes. 
14 


102 

The  common  foundation  of  all  those  clusters  of 
Islands  discovered  in  the  Pacific,  as  well  as  those 
of  New  South  Wales,  is  of  coral  structure  ;  ex- 
tensive reefs  of  which  run  off  in  all  directions. 

Banks  of  coral  are  found  at  all  depths,  having 
no  communication  with  each  other —and  at  all  dis- 
tances from  land.  By  a  rapid  increase  they  ar- 
rive at  or  near  the  surface,  when  winds  and  waves 
force  up  loose  fragments  from  deeper  water,  and, 
an  accumulation  thus  going  forward,  islands  are 
seen  in  all  the  different  stages  of  progressive  for- 
mation— as  shoals  first — then  as  reefs  or  breakers 
— eventually  as  bare  rock  above  the  water,  and 
finally  in  their  state  of  perfection,  covered  with  soil, 
and  adorned  in  all  the  beauties  of  vegitation. 

Kotzebue  in  his  voyage  to  the  Pacific,  and  Capt- 
Flinders,  in  his  account  of  New  South  Wales,  have 
each  given  many  pages  to  these  interesting  produc- 
tions. 

It  seems  probable  that  when  these  little  animals 
have  commenced  their  labours,  and  have  ceased 
to  live,  their  structures  adhere  together — and  the 
small  interstices  being  filled  with  sand,  a  solid 
rock  is  soon  the  consequence.  Future  races  con- 
tinue to  erect  their  habitation  on  the  rising  bank, 
and  die  in  turn,  while  elevating  this  monument  of 
their  labours.  It  is  by  a  surprising  instinct  that  in 


103 

the  early  stages  of  their  labour,  they  work  perpen- 
dicularly ;  and  as  they  erect  their  wall  chiefly  in 
situations  where  the  winds  are  constant,  they  thus 
afford  a  shelter  to  the  leeward,  whence  their  in- 
fant colonies  are  sent  off.  It  is  owing  to  this  that 
the  windward  side  of  a  reef  of  coral  is  always  the 
highest  part,  rising  sometimes  perpendicularly 
from  the  depth  of  200  feet,  or  perhaps  as  many 
fathoms. 

It  seems  necessary  to  our  busy  labourers  to  be 
covered  with  water,  in  order  that  their  work  may 
be  uninterrupted,  for  as  soon  as  the  reef  has  reach- 
ed such  a  height  as  to  remain  almost  dry  at  low 
water,  at  the  time  of  ebb,  the  corals  cease  to  build 
higher ;  sea-shells,  fragments  of  corals,  echinae  and 
their  broken  off  prickles  become  united  by  the 
burning  sun,  through  the  medium  of  the  cementing 
calcareous  sand  which  has  arisen  from  the  pulveri- 
zation of  the  shells,  into  one  whole  or  solid  stone ; 
and  this,  strengthened  by  the  continual  throwing 
up  of  new  materials,  gradually  increases  in  thick- 
ness, till  at  last,  it  becomes  so  high  as  only  to  be 
covered  by  the  high  tides  of  particular  seasons. — 
The  solar  rays  so  heat  this  mass  when  it  is  dry, 
that  it  splits  and  breaks  off  into  flakes.  These 
flakes  are  again  thrown  upon  each  other  at  high 
tides.  The  active  surf  throws  blocks  of  coral 


104 

(sometimes  6  or  8  feet  long  and  3  or  4  thick)  and 
shells  of  marine  animals  between  and  upon  the 
foundation  stones  :  after  this  the  calcareous  sand 
lies  undisturbed,  and  offers  to  the  seeds  of  plants 
and  trees  cast  upon  it  by  the  waves,  a  soil,  upon 
which  they  rapidly  grow  to  overshadow  its  daz- 
zling white  surface.  Entire  trunks  of  trees,  car- 
ried by  rivers  from  other  countries  and  islands,  find 
here,  at  length,  an  accidental  resting  place.  With 
these  come  some  small  animals,  as  lizards  and  in- 
sects, as  the  first  inhabitants.  The  sea  bird 
nestles  there,  and  by  feathers,  &c.  contributes  to 
the  formation  of  a  soil — sea  plants  now  take  root 
upon  it — a  cocoa  nut  is  cast  on  shore — stray  land 
birds  find  it  a  refuge — the  seeds  of  shrubs  and 
trees  are  thus  carried  there,  and  when  the  work 
has  long  been  completed,  man  also  appears,  builds 
his  hut  on  the  fruitful  soil  formed  by  the  corrup- 
tion of  the  leaves  of  the  trees,  and  styles  him- 
self lord  and  proprietor  of  this  new  creation. 


But  of  all  the  changes  arising  from  causes  now 
m  actual  operation,  those  resulting  from  the  agen- 
cy of  Subterranean  Heat,  by  Volcanoes  and  Earth- 
quakes, are  the  most  remarkable  and  interesting. 

The  time  allotted  allows  me  to  cast  but  a  cur- 


105 

sory  glance  at  a  few  of  the  facts  in  connection  with 
these  phenomena,  which  often  in  a  few  minutes 
change  the  whole  surface  of  a  country. 

In  the  earlier  periods  of  our  globe,  these  fires 
seem  to  have  been  more  extensively  in  action  than 
at  present ;  as  is  proved  by  the  many  remains  of 
extinct,  volcanoes  of  great  size  which  we  find  in 
various  parts  of  the  world,  and  by  the  existence  of 
rocks  nearly  allied  to  volcanic  products  in  almost 
every  country. 

Of  the  structure  of  these  mountains,  I  shall  only 
say  that  they  are  generally  truncated  cones,  with  an 
aperture  in  the  centre,  called  the  Crater,  whence 
the  eruptions  issue  :  but  not  unfrequently  they 
break  out  at  the  side  or  foot  of  the  mountains ; 
and  occasionally  under  the  sea — and  are  then 
termed  Submarine  Volcanoes,  or  Eruptions. 

Most  of  them  are  situated  near  the  Ocean,  or  to 
Lakes,  whence  many  Geologists  have  supposed 
that  water  forms  one  of  the  chief  agents  in  vol- 
canic phenomena. 

When  single,  they  have  a  pyramidal  or  conical 
form,  ascending  at  a  moderate  angle  of  inclina- 
tion from  the  base  to  an  elevated  plain,  from  the 
centre  of  which  rises  the  principal  crater. 

No  burning  Volcano  situated  in  a  chain  of  moun- 
tains is  to  be  found  in  Europe  or  Asia — they  be- 


106 

ing  generally  at  a  distance  from  them.  On  the 
American  Continent,  on  the  contrary,  Volcanoes 
of  the  most  stupendous  size  form  part  of  the  Cor- 
dilleras. In  the  south  of  the  province  of  Quito,  in 
Chili,  and  in  Guatimala,  they  are  grouped  in  rows. 
Baron  Humboldt — than  whom  no  man  has  ever 
visited  a  greater  number,  or  drawn  more  philo- 
sophical deductions,  in  regard  to  them,  has  made 
the  following  observations,  viz. 

1.  That  Mountains  with  slender  conical  peaks 
have   eruptions  of  the  greatest  violence  and  at  the 
shortest  intervals — as  Cotopaxi,Peak  of  Teneriffe, 
and  Orizava  in  Mexico. 

2.  Those  with  long  summits,  rugged  and  rocky, 
are  nearly  extinguished — as  Hecla  in  Iceland,  and 
many  in  South  America. 

3.  That  rounded  summits  indicate  in  many  pla- 
ces porphyritic  lava,  that  has  been  heated   and 
raised    up,   but    never    burst    forth    as     Chim- 
borazo,  and  the  greater  Sarcony  in  Auvergne. 

All  Volcanic  Mountains  have  the  cone,  or  su- 
gar loaf,  as  it  is  appropriately  called,  covered  with 
scoria?,  or  cinders  and  ashes.  1  myself  believe  that 
the  whole  cone  is  composed  of  such  substances  as 
have  been  ejected  once,  at  least,  those  nearest 
the  heat  being  again  consolidated.  It  has  been 
usual  for  travellers  to  state,  that  from  the  brim  of 


107 

the  crater,  it  was  easy  to  see  the  boiling  lava  with- 
in. This  good  fortune  did  not  attend  me,  as  I 
found  it  not  only  dangerous,  but  impossible  to  get 
within  such  distance  of  the  crater  of  Vesuvius, 
during  an  eruption,  as  to  allow  the  angle  of  vision 
to  be  more  than  45°.  But  even  had  it  been  possible 
to  stand  on  the  very  rim  of  the  crater,  and  cast  the 
eye  directly  downwards,  the  thick  cloud  of  smoke 
hanging  within,  would  have  concealed  the  burning 
mass. 

The  shape  of  the  crater  is  constantly  varying 
with  every  new  eruption.  Its  size  does  riot  de- 
pend on  the  elevation  or  mass  of  the  Volcanic 
Mountain.  Vesuvius  is  a  small  hill  compared 
with  the  Peak  of  Teneriffe,  and  it  has  a  crater  five 
times  larger.  The  Volcanoes  of  the  Andes  have 
all  small  openings,  and  there  are  many  reasons  for 
believing,  that  the  size  of  the  opening  diminishes 
as  the  elevation  of  the  mountain  is  greater,  were  it 
not  that  those  of  Cotopaxi  and  Rucipichinca  have 
craters  three  fourths  of  a  mile  in  diameter. 

The  depth  of  a  crater  varies  continually  in  ac- 
tive volcanoes ;  but  in  those  long  dormant,  it  under- 
goes no  change  excepting  that  produced  by  the 
occasional  fall  of  part  of  its  wall.  In  this  case  it 
allows  of  actual  measurement :  thus  the  crater  of 
the  Peak  of  Teneriffe  is  105  feet  deep. 


108 

The  whole  cone  of  a  Volcano  is  sometimes 
swallowed  up  during  an  eruption,  leaving  a  larger 
circular  crater,  at  a  less  elevation,  which  finally 
becomes  dormant,  and  forms  a  Lake.  Such  is  the 
celebrated  Lake  of  Avernus,  and  that  of  Agnano, 
near  Naples. 

Independent  of  the  destructive  changes  pro- 
duced by  the  burning  lava,  and  by  the  scoriae  fal- 
ling in  showers  around  the  crater  whole  mountains 
are  sometimes  formed  at  one  eruption  ;  thus  Monte 
Nuovo  about  10  miles  from  Naples  was  raised  in 
one  night ;  and  Morite  Rosso  on  Etna,  with  a  base 
of  2  miles  in  circumference,  and  a  height  of  750 
feet,  is  composed  of  the  scoriae  that  fell  after  one 
eruption  of  1 569.  The  color  of  the  mass  of  ma- 
terials of  this  last  mountain  is  generally  reddish,  as 
the  name  denotes,  and  the  scoriae  contains  em- 
beded  schorl. 

In  the  intendancy  of  Valladolid,  in  New  Spain, 
is  an  immense  plain  belong  to  the  plantation  Jorul- 
lo,  2600  feet  above  the  sea,  and  cultivated  during 
the  last  century  with  cane  and  indigo,  having  its 
elevations  crowned  with  evergreen  oaks,  and 
palm  trees.  After  some  admonitory  warnings,  a 
tract  of  ground,  in  this  place,  to  the  extent  of  10 
miles,  rose  in  the  shape  of  a  bladder,  being  about 
40  feet  at  the  edges,  and  534  feet  at  the  centre 


109 

above  its  former  level.  Many  mountains  soon  after 
rose  on  different  parts  of  it,  the  most  elevated  of 
which  is  the  Volcano  Jorullo. 

There  are  other  proofs  of  the  reason  we  have  to 
consider  internal  heat  as  an  active  agent  in  the 
production  of  Geological  phenomena  :  but  these 
will  suffice. 

I  have  abstained  from  entering  into  minutiae  con- 
cerning any  one  volcano.  Having  visited  some  of 
the  most  celebrated  in  Europe,  I  may  perhaps  be 
indulged,  at  the  risk  of  an  imputation  of  egotism, 
in  briefly  relating  a  few  particulars. 

In  1819, 1  had  the  satisfaction  of  seeing  and  of 
visiting  Vesuvius  during  an  eruption.  The  dark- 
ness of  the  night,  the  time  I  had  chosen,  (for  my 
first  visit)  rendered  the  scene  more  awful  and  sub- 
lime. In  ascending  the  cone,  we  traversed  beds  of 
lava  that  but  a  few  days  before  had  been  vomited 
forth :  Although  the  surface  was  black,  the  interior 
was  still  a  heated  mass  ;  and  we  saw  the  yet  red 
lava  through  the  small  cracks  in  the  surface.  On 
inserting  through  these  fissures  the  sticks  we  had  in 
our  hands,  they  were  immediately  withdrawn  on 
fire.  We  could  not  approach  within  6  feet  of  the 
rim  of  the  crater,  and  even  by  crawling  could  not 
get  our  faces  near  the  edge,  so  as  to  see  the  bot- 
tom— or  indeed  any  thing  but  a  mass  of  cloud  ob- 
15 


110 

structing  the  sight.  The  dreadful  bellowing  and 
roaring  of  the  interior  was  indeed  awful,  and  at  in- 
tervals a  sudden  and  tremendous  explosion  warn- 
ed us  of  the  shower  of  stones,  that  ascending  in  the 
flames,  were  to  fall  red  hot  around  us.  These 
stones  were  of  all  sizes,  and  we  endeavored  to 
escape  the  shower  by  running  down  the  cone. 

About  100  feet  below  the  brim  of  the  crater, 
through  a  hole  in  its  side,  gushed  a  constant  stream 
of  liquid  lava.  It  appeared  of  the  consistency  of 
molten  iron,  and  flowed  slowly  in  the  channel  it 
had  formed  for  itself.  From  this  liquid  mass  we 
contrived,  by  the  aid  of  poles,  to  detach  small 
masses,  in  which  we  inserted  each  some  small  arti- 
cle, while  the  lava  was  pliable.  Some  silver  that  I 
had  in  my  pocket,  jand  my  watch  key,  were  among 
the  articles  thus  forced  into  the  liquid  lava,  which 
then  cooled  around  them :  as  you  now  see  them. 

Having  retired  about  100  yards  from  this  burn- 
ing river,  and  thrown  aside  some  of  the  smaller  cin- 
ders so  as  to  form  a  small  excavation  on  the  spot 
where  a  current  of  heated  air  was  escaping,  which 
served  to  keep  us  warm,  we  took  our  supper,  and 
lighting  our  torches  by  the  lava,  wrote  letters  to 
our  friends — and  then  slept,  for  an  hour,  before 
the  glorious  orb  of  day,  rejoicing  in  the  east,  call- 
pd  us  to  tho  summit  to  behold  its  splendor. 


Ill 

There  are  36  eruptions  of  Vesuvius  on  record 
previous  to  1 806,  since  when  they  have  been  almost 
annual.  The  bed  oflava  runs  for  many  miles,  and 
often,  as  you  are  all  aware,  destroys  towns  and 
cities. 

Villages,  and  woods  and  rocks 

Fall  flat  before  its  sweep. — The  region  round, 
Where  myrtle  walks,  and  groves  of  golden  fruit 
Rose  fair  ;  where  harvest  waved  in  all  its  pride ; 
And  where  the  vineyard  spread  its  purple  store, 
Maturing  into  nectar  ;  now  despoiled 
Of  herb,  leaf,  fruit  and  flower,  from  end  to  end, 
Lies  buried  under  fire,  a  glowing  sea ! 

Mount  Etna,  in  Sicily,  had  been  long  dormant, 
when  in  1819, 1  visited  that  volcano.  Monti  Gi- 
bello,  or  Monte  Bello,  (from  Mongibello,  Mount  of 
Mounts)  as  it  is  called  by  the  inhabitants,  has  been 
so  often  visited  and  described,  that  it  is  needless, 
nor  would  it  be  proper,  for  me,  here,  to  enter  into 
a  detail  of  its  history  or  its  beauties.  Relative  to 
its  history,  it  may  be  observed,  that  doubts  have 
arisen  as  to  its  origin ;  which  shall  be  spoken  of  in 
another  place ;  here  it  is  only  necessary  to  observe 
that  Count  Borch,  and  some  other  Geologists  con- 
sider Etna  as  a  Granitic  Mountain,  containing 
abundance  of  lead  and  copper,  merely  covered 
by  volcanic  products.  In  proof  of  which,  it  is 
alleged,  that  on  the  mountain  shells  exist  at  the 


112 

height  of  2000  feet  above  the  sea — and  that  strala 
of  clay  with  marine  shells  are  found  2400  feet 
above  the  sea,  dipping  towards  it ;  and  which  pro- 
bably had  been  formed  there  while  the  mountain 
was  progressively  rising  from  the  ocean.  But  I 
consider  Etna  as  an  assemblage  of  mountains, 
piled  on  each  other,  and  which  have  been  pro- 
duced by  different  eruptions  from  many  volcanic 
openings,  most  of  which  are  now  dormant  :  and 
that  the  whole  mass  is  thus  an  accumulation  of 
volcanic  products.  Monte  Nuovo  and  nearly  fifty 
other  mountains  on  that  side  of  Etna  next  to  Cata- 
nia are  formed  wholly  of  ejected  substances. — 
Many  of  them  are  now  covered  by  a  fertile  soiK 
though  still  exhibiting  the  crater  well  deiined. 

After  leaving  the  luxuriant  and  fertile  region  that 
skirts  the  base  of  the  mountain,  and  forced  our 
mules  over  the  sterile  band,  near  to  the  regions  of 
eternal  snow,  we  passed  this  frozen  zone  on  foot,, 
and  reached  the  cone,  which  we  ascended.  The 
lower  half  was  covered  with  snow.  The  upper 
portion,  nearly  half  a  mile,  was  clear  to  the  brim  of 
the  crater.  From  the  surface  of  this  brim  or  edge, 
Avhich  was  hot  to  the  feet,  arose  heated  air,  strong- 
ly impregnated  with  sulphur.  As  this  air 
or  gas  oozed  through  the  surface  it  deposited 
beautiful  and  brilliant  crystals  of  sulphur.  On 


breaking  up  the  crust  with  our  sticks,  we  saw  them 
glistening,  and  collected  quantities  of  them  :  some 
of  which  are  now  on  this  table. 

The  interior  of  the  crater  was  covered  with  snow1 
near  the  bottom; — except  the  northern  side, 
which  rose  a  solid  wall,  separating  it  from  another 
crater.  From  cracks  in  this  wall,  and  from  a  few 
small  openings  in  the  bottom,  a  thin  white  smoke 
was  gently  ascending,  and,  in  small  quantity, 
gracefully  curling  itself  into  the  atmosphere. 

We  descended  some  distance  into  the  crater,  in 
pursuit  of  specimens  of  the  many  crystals  known 
to  exist  among  the  products  of  this  volcano. 

It  was  a  mild  and  lovely  evening,  when,  after 
having  been  refreshed  at  St.  Nicoloso,  we  continued 
our  way  to  the  summit,  so  as  to  be  there  by  sun- 
rise. 1  only  mention  this  to  add  that  during  our 
ascent,  we  found  it  extremely  cold  before  we 
reached  the  frozen  region — and  that  we  beheld  at 
the  same  time  a  thunder  storm  some  distance  at  sea. 
On  leaving  the  summit  for  our  descent,  we  experi- 
enced all  the  vicissitudes  of  climate,  extreme 
cold,  a  snow  storm,  and  several  violent  showers  of 
rain,  with  alternate  intervals  of  a  scorching  and 
brilliant  sunshine. 

We  are  all  aware  of  the  distance  often  run  by 
the  lava  from  this  volcano.  Catania,  nearly  40 


114    . 

miles  from  its  summit,  has  often  been  destroyed  by 
it.  Taormina,  about  the  same  distance  on  another 
side  of  the  mountain,  has  often  suffered  the  same 
fate.  In  its  vicinity  is  found  a  beautiful  red  lava. 

The  base  of  Etna  covers  a  circumference  of 
about  36  miles  ;  and  on  its  sides  are  not  fewer 
than  80  cities,  towns,  and  villages,  and  allowing 
from  1200  to  1500  persons  to  each,  it  may  be  safe- 
ly stated  that  there  are  100,000  people  inhabiting 
voluntarily  the  crust  of  this  immense  volcano. 


One  of  the  latest  submarine  volcanoes  of  which 
we  have  an  account,  was  that,  which,  in  1811, 
burst  forth  in  the  Azores,  near  St.  Michaels. 

Immense  clouds  of  black  smoke  were  observed 
to  rise  from  the  surface  of  the  sea,  when,  suddenly 
a  column  of  cinders,  ashes,  and  stones  shot  up  with 
great  violence,  accompanied  by  a  grumbling  noise 
and  vivid  flashes  of  lightning. 

The  depth  of  water  at  the  spot  was  formerly 
180  feet.  The  quantity  of  ashes  and  scoriae  was 
so  great  that  on  the  fourth  day  the  accumulation 
was  seen  to  rise  above  the  water,  forming  the  rim 
of  the  crater,  which  thus  was  reared  among  the 
waves. 


115 

The  island  of  Sabrina,  thus  formed,  rose  about 
250  feet  from  the  sea,  with  a  circumference  of 
about  a  mile,  at  the  waters  edge. 

A  similar  island  arose  many  years  since,  near  to 
Tercira,  of  the  same  group,  in  a  single  night. 

The  islands  that  have  been  produced  by  sub- 
marine volcanoes  in  the  Grecian  Archipelago,  are 
among  the  most  remarkable  products  of  these 
phenomena. 

We  all  know  that  volcanoes  eject  many  sub- 
stances beside  lava — and  that  cinders  and  ashes 
are  sometimes  projected  to  a  great  distance.  The 
celebrated  Pompeia,  which  has  so  often  been  de- 
scribed by  other  persons  who  have  visited  the  in- 
teresting ruins,  was  covered  by  ashes  showered 
upon  it  from  Vesuvius,  (from  which  it  is  distant 
about  12  miles)  in  the  year  79  of  the  Christian  era. 

Intimately  connected  with  the  preceding  phe- 
nomena, both  as  to  cause  and  effect,  is  that  dread- 
ful convulsion  of  nature,  for  which  no  word  in  any 
language  has  yet  been  found  to  convey  an  idea 
sufficiently  appalling.  No  word  can  impress  upon 
the  mind  the  terror  it  occasions.  The  extensive, 
immediate,  and  awful  consequences  of  the  earth- 
quake, leave  no  hope,  no  refuge  for  the  alarmed 
individual — no  refuge  but  the  refuge  of  despair. 


116 

There  is  no  country  that  is  not  more  or  less 
affected  by  them  :  even  the  sea  is  subject  to  them. 

The  annals  of  the  world  mark  no  week,  per- 
haps no  day,  that  is  not  a  record  of  their  devastation 
— No  accurate  account  of  the  cause  of  earth- 
quakes has  been  handed  to  us  by  preceeding 
philosophers.  All  their  investigations  ended  in 
supposition,  instead  of  collection,  comparison,  and 
reflection. 

One  of  the  earliest  earthquakes  on  record  since 
the  Christian  era,  was  that  which,  under  Tiberius, 
destroyed  in  one  night  12  cities  in  Asia  Minor,  in 
a  circumference  of  about  300  miles  in  diameter. 
It  is  remarkable  that  no  other  changes  took  place- 
no  springs  or  fountains  were  dried  up,  the  course 
of  no  river  altered — no  hill  overthrown — but  all 
remains  the  same  at  the  present  day. 

The  history  of  the  violent  earthquakes  that  in  the 
sixty  third  and  succeeding  years  of  our  era,  preced- 
ed those  eruptions  of  Vesuvius,  which  destroyed 
Herculaneum  and  Pompeia,  and  in  which  the  el- 
der Pliny  lost  his  life,  is  familiar  to  most  of  us. 

During  that  fearful  one  which  preceded  the  erup- 
tion of  Vesuvius  on  Sept.  28,  1 538,  the  Lucrine 
lake  near  Naples  was  lost — a  whole  town  and  all 
its  inhabitants  swallowed — a  tract  of  ground  near 
Lake  Avernus  rose  up,  and  in  one  night  Monte 


117 

Nuovo  (formerly  mentioned)  arose,  and  next  morn- 
ing showed  an  elevation  of  1127  feet  above  the 
level  of  the  sea.  The  whole  country  was  destroy- 
ed, and  in  24  hours  not  even  the  vestige  of  a  habi- 
tation was  to  be  discerned. 

The  famous  Earthquake  of  1755  that  destroyed 
Lisbon,  and  that  which  in  1783  convulsed  Calabria, 
are  the  most  important  on  modern  records.  A 
mere  outline  of  either  would  occupy  an  hour. 

Of  the  violence  of  the  former  we  may  form  some 
idea,  when  we  know  that  it  was  severely  felt  over  all 
Spain — (except  Catalonia,  Arragon,  and  Valencia) 
—that  in  Africa  it  was  almost  as  severe  as  in  Eu- 
rope— that  it  was  felt  in  England,  Scotland,  Nor- 
way, Sweden,  Germany,  Holland,  Switzerland  and 
Corsica — even  in  Antigua  and  Barbadoes — nay, 
even  on  the  shores  of  Lake  Ontario.  At  Lisbon 
it  began  25  minutes  past  9  in  the  morning.  Be- 
tween 9  and  1 0  the  master  of  a  vessel  bound  to  the 
West  Indies,  being  then  in  north  lat.  25,  and  west 
long.  40,  and  many  miles  from  land,  heard  a  vio- 
lent noise,  and  perceived  his  ship  agitated  as  if  by 
a  sudden  jerk — He  started  in  great  terror,  and 
perceived  through  the  cabin  window  land  at  the 
distance  of  about  a  mile,  which,  when  he  got  on 
deck,  had  disappeared.  In  another  minute  three 
rocky  pinnacles  rose  from  the  sea  and  spouted  wa- 


148 

ter,  and  a  heavy  dense  cloud,  which  ascended,  and 
left  no  trace  of  the  rocks.  Another  vessel,  be- 
tween 9  and  10  the  same  morning,  about  40 
leagues  from  St.  Vincent,  was  violently  jerked,  as 
if  she  had  struck  a  rock,  and  all  hands  on  board 
were  thrown  down.  The  sea  was  agitated  for  a 
minute,  and  then  no  trace  of  rock  or  storm  ap- 
peared. 

The  Earthquakes  of  Calabria  were  equally  aw- 
ful. Kircher,  who  witnessed  one  in  1 638,  publish- 
ed a  long  and  interesting  account  of  it.  Hir  Wil- 
liam Hamilton  has  given  a  valuable  and  accurate 
statement  of  the  convulsions  of  this  unhappy  coun- 
try, from  which  it  appears,  that  in  one  year,  1783, 
it  suffered  from  949  Earthquakes. 

Their  effects  are  still  visible  :  I  have  witnessed 
some  of  them  with  an  anxiety  of  mind  not  to  be  im- 
agined. The  ordinary  action  of  the  elements  can 
never  efface  them.  It  can  only  be  effected  by 
some  convulsion  even  more  terrible  than  its  pre- 
decessors. 

It  will  easily  be  imagined  that  as  Heat  is  (he 
prime  agent  of  one  of  the  prevalent  Geological 
theories,  and  is  so  intimately  connected  with  Vol- 
canoes and  Earthquakes,  that  many  disputes  have 
arisen  on  the  subject.  They  may  however  be 


reduced    to  three,  viz. — as  to   the  Intensity,  the 
Situation,  and  the  Origin  of  Volcanic  Fire. 

Messrs.  Le  Sage  and  Deluc,  and  afterwards  Do- 
lomieu,  made  a  series  of  experiments  on  Lava, 
which  was  found  to  vitrify  more  completely  in  fur- 
naces than  in  volcanoes ;  and  many  crystals  that 
were  embedded  in  it  were  easily  fused  ;  whence 
they  concluded  that  volcanic  fire  was  not  so  very 
intense,  and  that  its  effects  were  caused,  rather  by 
extension  and  duration,  than  by  activity.  Sir  Jas. 
Hall  overthrew  the  force  of  these  experiments  as 
far  as  vitrification  was  concerned  ;  inasmuch  as 
vitrification,  according  to  his  experiments,  does  not 
depend  so  much  on  the  degree  of  heat,  as  on  the 
rapid  cooling  of  the  stone  or  lava. 

He  was  further  confirmed  by  the  valuable  ex- 
periments of  Mr.  Watt,  proving  that  if  the  process 
of  cooling  be  very  slow  indeed,  a  crystalline  ar- 
rangement of  the  particles  is  the  consequence. 

Observations,  made  by  men  who  are  capable  of 
judging,  are  far  more  important  and  conclusive 
than  any  experiments  ;  and  from  a  comparison  of 
these  we  are  entitled  to  conclude,  that  sometimes 
the  heat  of  volcanoes  exceeds  that  of  the  most  pow- 
erful artificial  furnaces  :  but  that  the  fluidity  and 
heat  of  lava  does  not  always  indicate  such  intense 
heat.  Spallanzani  passed  a  current  of  lava  upon  Et- 


120 

na,  that  flowed  1 1  months  previously  and  which 
was  still  red  hot  at  some  distance  beneath  the  sur- 
face. The  A  bbe  Ferrara  mentions  that  when  in  1 709 
they  opened  at  Catania  the  current  which  flowed 
from  Monte  Rosso  40  years  before,  flames  broke 
forth,  and  the  retained  heat  was  so  great  even  at 
the  beginning  of  this  century,  that  rain,  when  it 
fell  upon  it,  passed  off  immediately  in  vapour. 

Upon  opening  some  houses  in  Torre  del  Greco, 
nearly  buried  in  the  lava  of  Vesuvius  in  1794,  iron 
utensils  were  found  partially  volatilized,  and  some 
crystals  of  iron  (specular)  discovered  on  the 
surface. 

We  know  on  the  other  hand  that  many  crystals, 
easily  fusible  by  the  blow  pipe,  are  ejected  unal- 
tered by  volcanoes.  In  the  list  of  substances  vomi- 
ted forth,  we  find  many  that  were,  and  many  that 
were  not  fused.  Here  is  a  specimen  that  sets  all 
caballing  at  rest — a  piece  of  lime,  with  an  embed- 
ed  shell,  sent  forth  during  an  eruption  of  Vesuvius, 
and  presented  to  me  by  Sig.  Monticelli,  so  well 
known  as  having  indefatigably  studied  this  volcano 
for  many  years. 

As  to  the  Situation  of  volcanic  fire,  viz.  whether 
it  originates  in  the  mountain  itself,  or  is  placed  at 
a  great  depth  below  the  surface  :  It  has  been  sup- 
posed that  rolcanoes  originally  break  out  in 


121 

mountains  already  formed,  and  merely  cover  them 
with  lava  and  scoriae.  For  instance,  that  Vesuvius 
and  Etna  were  always  mountains,  either  primary 
or  secondary,  and  that  volcanic  fire  has  only  alter- 
ed their  forms  perhaps,  and  covered  the  surface 
with  lava,  &c.  On  the  other  hand,  it  is  asserted 
that  these  mountains  are  entirely  produced  by  sub- 
terranean heat,  and  composed  of  the  lava  and 
scoriae  thrown  up— as  the  Monte  Rosso  (already 
noticed)  and  Monte  Nuovo,  near  Naples  :  or  else 
that  they  have  been  raised  by  subterranean  heat, 
which  has  softened  and  elevated  the  strata  above 
it,  as  mentioned  in  the  tract  of  land  in  South  Ameri- 
ca, and  on  this  a  volcanic  crater  had  been  formed 
similar  to  the  Jorullo. 

To  a  calm  and  unimpassioned  man,  to  the  phi- 
losopher, both  of  these  views  will  appear  nearly 
correct.  There  can  be  no  doubt  that  Monte  Ros- 
so, Monte  Nuovo  and  Jorullo  were  formed  by  er- 
uptions even  had  we  not  the  testimony  of  witnesses; 
and  we  are  justified  in  concluding  that  the  source 
of  the  heat  was  far  below  the  base  of  these  hills. 
But  there  are  many  other  volcanoes,  to  which  such 
origin  cannot  be  attributed.  On  Etna,  for  instance, 
we  find  calcareous  strata,  with  imbedded  remains  of 
shell  fish  resting  on  beds  of  volcanic  tufa,  and  dip- 
ping to  the  sea.  Here  the  inference  is  plausible, 


122 

that  the  first  eruption  took  place  beneath  the  sea, 
and  that  the  strata  with  marine  organic  remains 
were  deposited  before  the  mountain  rose  from  the 
ocean.  In  fine,  that  the  volcano  existed  be- 
fore the  mountain — that  its  first  eruption  was 
submarine,  and  the  whole  masses  subsequent- 
ly elevated,  or  the  sea  depressed.  The  same 
may  be  said  of  the  Peak  of  Teneriflfe  and  of 
the  Canary  Islands.  There  is  a  great  difference 
between  the  elevating  and  breaking  up  of  strata, 
and  the  mere  accumulation  of  lava  and  scoriae,  of 
which  the  celebrated  Island  Sabrina  was  formed 
in  181 1  off  St.  Michaels  in  the  Azores.  It  is  prov- 
ed by  both  phenomena  that  the  location  of  volcanic 
fire  is  far  below  the  surface.  Were  it  placed  in 
the  mountain  itself,  we  cannot  conceive  why,  after 
burning  1000  years,  the  walls  do  not  fall  in  ;  and 
when  once  extinguished  it  would  be  very  strange 
that  it  should  occur  again  in  precisely  the  same 
spot. 

The  supposition  of  the  School  of  Werner,  that 
volcanic  fire  is  seated  in  coal  beds,  is  very  inade- 
quate : — the  depth  would  riot  be  great  enough  for 
the  production  of  the  consequences — the  sides  here 
too  would  fall  in  ;  and  why.  when  once  burned 
out,  and  extinct  for  700  years  and  upwards,  should 


123 

it  break  forth  again  in  the  same  place  ?  A  coal 
pit  near  New-Castle  (upon  Tyne)  took  fire  in 
1648,  and  burned  for  40  years,  when  it  was  ex- 
tinguished, without  a  sign  of  volcanic  fire. 

Some  philosophers  have  supposed  that  fire  ex- 
isted universally  in  the  bowels  of  the  Earth,  and 
that  the  contact  of  water  with  it  produced  steam, 
the  immediate  cause  of  Earthquakes,  which,  when 
it  found  an  opening,  was  expelled  in  the  form  of  an 
eruption.     Thus,  they  say,  the  Earthquakes  of  Ca- 
iabria^and  Sicily   were  always   accompanied   by 
eruptions  of  Vesuvius   or  Etna :  thus,   during  the 
Earthquakes,  formerly  mentioned,  of  Lisbon,  fire 
was  seen   to  rise  in  the  middle  of  the  Atlantic  : 
thus  the  Earthquakes   of  New  Andalusia  and  the 
West  Indies  are  connected  with  the  volcanoes  of 
the  Andes  :  thus,  when  Caraccas  was  destroyed  in 
1812,  St.Vincent,  dormant  for  100  years,  broke  out 
afresh.   The  night  when  Callao  and  Lima  were  de- 
stroyed, four  new  volcanoes  appeared  on  the  Andes. 
All  these  circumstances  probably  gave  rise  to  the 
opinion  prevalent  among  the  vulgar  in  some  parts  of 
the  world,  that  the  interior  of  our  globe  is  the  De- 
vil's workshop,  to  which  volcanoes  are  the  chim- 
nies.     The  bottom  of  the  Mediterranean  between 
Sicily,  the  Lipari  Islands  and   Naples,  is  covered 
with  volcanic  substances  :  and  Humboldt  considers 


124 

the  Mountains  of  Quito,  700  square  leagues,  in 
extent,  one  immense  volcano,  throwing  out  flames 
at  different  cones. 

The  Origin  of  volcanic  fire  was  formerly  attribu- 
ted to  fermentation  below  the  surface,  which  was 
not  only  explained  and  illustrated,  but  a  recipe  for 
making  them  composed. 

If  any  of  you  wish  for  a  volcano  on  a  small  scale 
in  your  garden,  take  25  Ib.  of  powered  sulphur,  and 
as  much  iron  filings,  mix  them  into  a  paste  with  wa- 
ter and  place  the  whole  in  a  large  iron  pot,  covered 
with  a  cloth,  some  little  distance  under  ground. 
In  a  few  hours,  from  9  to  12,  the  earth  swells,  heats 
and  cracks — hot  sulphurous  vapours  arise,  and 
the  cracks  enlarging,  a  brilliant  flame  bursts  up, 
thus  forming  a  volcano  in  miniature,  spontaneously 
produced  by  the  reciprocal  action  of  water,  iron 
and  sulphur.  Thus  spontaneous  combustion  was 
supposed  to  arise  from  the  contact  of  water  with 
iron  pyrites,  which  contains  both  iron  and  sulphur. 
A  district  in  Dorsetshire  (Eng.)  abounding  in 
pyrites,  after  a  heavy  rain,  in  a  hot  summer,  took 
fire  and  burned  for  a  long  time. 

Sulphur  and  Bitumen  have  been  supposed  t6 
give  rise  to  volcanic  phenomena  ;  but  though  sul- 
phur always  is,  bitumen  has  never  been  found  in 


125 

volcanic  products.  Monticelli  has  lately  detected 
free  sulphuric  acid,  an  important  discovery. 

The  true  cause  of  volcanic  fire  is  probably  not 
to  be  sought  for  in  the  combustion  of  such  inflam- 
mables as  we  find  on  the  surface  of  our  globe ;  but 
in  the  chemical  combination  of  elementary  matter 
composing  mineral  substances. 

The  existence  of  volcanic  fire,  then,  is  proved 
by  the  fact  itself,  as  appearing  in  volcanoes  ;  the 
connection  of  volcanoes  with  each  other,  and  with 
earthquakes,  proves  its  situation  to  be  very  far  be- 
low the  surface ;  the  original  cause  of  this  fire,  and 
the  reason  of  its  breaking  out  occasionally  with 
greater  vio!ences  are  among  those  mysteries  which 
still  continue  to  elude  our  grasp — and  will  proba- 
bly remain  forever  hidden  from  the  knowledge  of 
mortals. 


LECTURE  IV. 

•Minerals  entering  into  the  composition  of  Rocks — 
Different  forms  of  Rocks — Masses,  Beds,  Strata,  JVb- 
dides,  Veins — Internal  Structure  of  Rocks — Laminar, 
Fibrous,  Spheroidal,  Prismatic,  Veined,  Cavernous. 

Amygdaloidal,  Aggregate,    Granular,    Porphvritic 

Texture — Fracture — -Hardness — Color — Frangibilily . 
— Lustre — Transparency — Specific  Gravity — diction  of 
Acids. 

Having  cursorily  glanced  at  (he  present  appear- 
ance of  our  globe,  and  at  the  changes  now  going 
forward,  from  various  causes,  on  its  surface,  we  pro- 
ceed to  examine  the  rocks  that  enter  into  its  com- 
position. Before  entering  upon  a  description  of 
them,  it  is  necessary,  however,  to  premise  that  a 
knowledge  of  Mineralogy  is  in  some  degree  essen- 
tial to  the  study  of  Geology,  of  which  it  has  been, 
not  unaptly,  styled  the  Alphabet.  Nearly  all  min- 
eral substances  are  found  either  as  constituents  of 
rocks,  or  as  occasional  substances  imbedded  in 
them. 

There  are  not  many  minerals  entering  into  the 
composition  of  rocks  :  The  following  enumeration 


127 


is  perhaps  complete.  For  a  knowledge  of  these 
substances  I  must  refer  you  to  some  treatise  on 
mineralogy — and  none  is  more  deserving  of  com- 
mendation than  that  of  Professor  Cleveland,  of 
Bowdoin  College. 


Clinkstone, 

Compact  Felspar, 

Quartz, 

Felspar, 

Carbonate  of  Lime, 

Mica, 

Chlorite, 

Talc, 

Hornblende, 

Actynolite. 


Augite, 

Serpentine, 

Steatite, 

Noble  Serpentine, 

Gypsum, 

Iron, 

Bitumen, 

Pitchstone, 

Chert. 


A  larger  number  of  substances  occur  imbedded 
in  rocks,  in  such  quantities  as  materially  to  alter 
the  character  of  the  matrices,  viz. 


Garnet, 

Olivin, 

Cyanite, 

Finite, 

Spodumene, 

Chiastolite, 

Staurotide, 

Epitode, 

Mesotype, 

Zircon, 

Topaz, 

Beryl, 


Chrysoberyl, 
Fluate  of  Lime, 
Corundum, 
Oxydulous  iron, 
Pyrites, 

Chromat  of  iron, 
Prehnite, 
Andalusite, 
Apatite, 
^phene, 
Oxyde  of  tin, 
Molybdena. 


It  is  not  too  much  to  say  that  every  variety  of 
mineral  is  found  imbedded  in,  or  connected  with 
some  rock. 


128 

Rocks    in    different  positions  assume    different 
forms  ;  which  may  be  reduced   to  five,  viz. 


IRREGULAR  MASSES, 


BEDS, 
STRATA, 


NODULES, 

VEINS, 


Irregular  Masses,  may  be  of  any  size ;  and  often 
constitute  mountains,  as  is  the  case  with  granite, 
serpentine,  porphyry,  and  the  overlying  rocks,  as 
trap,  &c. 

Beds  are  of  various  sizes ;  often  running  into  ir- 
regular masses  :  They  are  straight,  or  curved,  and 
frequently  intersected  by  joints,  so  as  to  assume  a 
cuboidai  appearance.  Few  rocks  assume  this  form : 
those  most  disposed  to  it  are  granite,  porphyry, 
syenite,  and  greenstone  or  hornblende.  This  dis- 
tinction is  considered,  by  Dr.  Macculloch,  as  be- 
ing practically  the  most  easy,  and  perhaps  the  only 
one  necessary  ibr  the  student.  Beds  and  irregu- 
lar masses  often  give  out  veins  that  penetrate  the 
adjoining  rocks. 

Strata  have  been  confounded  with  beds,  but  they 

r.o  v    •  [•'•''  v ' '  .•  -/  ••-••'    '*r,'f? 

are  generally  much  larger,  and   usually  are  more 

extensive  in  two  dimensions  than  in  the  third :  so 
that  strata  may  be  considered  as  immense  beds 
with  the  upper  and  lower  surfaces  parallel,  in  most 


129 

cases  ;  but  occasionally  meeting  at  a  very  acute 
angle.  Strata  do  not  necessarily  preserve  the 
same  thickness,  and  often  vary  in  the  course  of  a 
few  yards  ;  nor  are  they  always  straight ;  frequent- 
ly being  contorted  and  flexed  into  larger  or  smaller 
curvatures,  which  may  be  either  parallel  or 
transverse  to  the  plane  of  stratalication. 

This  form  of  rocks  is  of  various  extent,  some- 
times being  discernible  only  for  a  few  hundred 
yards,  and  at  others  being  well  defined  for  hun- 
dreds of  miles.  Strata  are  found  at  all  angles  with 
the  horizon,  and  in  all  relative  positions  to  each 
other  and  the  adjoining  rocks. 

A  rock  is  not  necessarily  of  the  same  modifica- 
tion through  the  whole  extent  of  a  stratum,  as  the 
texture  may  vary  to  the  widest  limits  of  fine 
and  coarse. 

Strata  never  send  off  veins  into  adjoining  rocks. 

Nodules,  or  imbedded  irregular  masses,  is  a  term 
lately  adopted  to  include  rocks  which  are  riot 
stratafied  nor  disposed  in  pseudo  strata  (beds),  and 
which  do  not  resemble  in  their  connections  other 
large  irregular  masses.  The  forms  of  the  Nodules 
are  various  ;  and  they  are  usually  imbedded  in 
the  stratafied  rocks  ;  but  occasionally  in  granite. 
The  size  varies  from  a  foot  to  a  mile.  Limestone. 


130 

Serpentine  and  compact  Felspar  alone  have  been 
found  of  this  rare  division  of  form. 

Feins  are  known  by  their  filamentary  forms,  and 
by  intersecting  all  other  forms  of  rocks  and  each 
other.  As  this  is  an  important  subject  and  one 
that  has  given  rise  to  much  Geological  disputation, 
it  may  be  well  to  enlarge  upon  it ;  premising  that 
the  school  of  which  Hutton  was  the  founder,  con- 
sider veins  to  have  been  filled  from  beneath  by 
the  action  of  fire  :  while  the  disciples  of  Werner 
maintain  that  .they  were  filled  from  above  by  aque- 
ous solution  and  infiltration  :  all  acknowledging 
that  they  occupy  places  or  fissures  originally  open. 

Veins  are  simple,  or  they  exhibit  branches  or 
ramifications  :  the  latter  are  more  generally  met 
with  in  Granite. 

The  size  of  veins  varies  from  a  mere  thread  to 
several  hundred  feet  in  breadth,  being  smallest 
usually  in  the  primary  rocks,  and  from  one  foot  to 
several  miles  in  length. 

The  relative  position  of  veins  is  extremely  di- 
versified, intersecting  rocks  in  all  directions,  form- 
ing every  possible  angle  with  the  horizon,  and 
dipping  to  every  point  of  the  compass  :  the  course 
of  a  vein  being  straight  or  flexed. 


131 

It  has  been  observed  that  veins,  except  those  of 
quartz  and  calcareous  spar,  are  limited  to  granite 
and  the  overlying  family,  or  the  traps,  syenite, 
and  porphyry. 

Rock  veins  are  often  traced  to  some  irregular 
mass,  though  not  in  all  instances.  They  may  tra- 
verse several  different  formations,  and  are  always 
different  from  the  rocks  they  traverse. 

Contemporaneous  veins  differ  from  true  veins 
in  many  particulars.  The  breadth  is  seldom  more 
than  a  few  inches,  the  length  varying  from  half  a 
foot  to  more  than  an  hundred  feet.  The  course  is 
scarcely  ever  straight ;  and  they  give  off  many 
branches.  They  are  usually  intimately  connected 
with  the  walls  of  the  rocks  in  which  they  occur — 
sometimes  passing  into  them  insensibly  differing 
but  little  in  composition,  and  often  being  one  of  the 
constituents.  Thus  granite  contains  contempo- 
raneous veins  of  quartz,  of  felspar,  and  of  mica. 
Gneiss  affords  them  of  the  same  substances.  Mi- 
ca slate,  into  the  composition  of  which  felspar 
does  not  enter,  contains  veins  of  quartz,  and 
of  mica,  and  of  the  two  variously  Wended. — 
They  never  traverse  more  than  one  bed  or 
stratum,  and  have  no  connection  with  any 
other  mass  of  the  same  substance.  They  seem  to 


132 

have  been  formed  at  the  same  time  with  the  rock 
in  which  they  are  found. 


The  walls  of  a  vein  are  the  sides  of  the  rock 
containing  it,  being  in  many  cases  the  sides  of  the 
fissure.  The  upper  and  lower  walls  are  called 
roof  and  floor,  or  pavement.  The  sides  of  many 
veins  are  usually  marked  by  thin  layers  of  some 
argillaceous  substance. 

Veins  often  intersect  each  other,  and  in  some 
cases  have  a  regular  structure,  being  filled  with 
different  substances  observing  a  parallelism  and 
the  same  order  from  both  walls  to  the  centre. 

Cross  courses  are  veins  not  being  metalliferous 
intersecting  metallic  veins. 

Sometimes  the  body  of  a  vein  and  the  surround- 
ing strata  seem  to  have  been  fractured,  and  part 


133 

of  it  to  have  fallen  down,  leaving  the  edges  no 
longer  in  continuity  :  this  is  called  a  shift  of  the 
strata — thus  : 


— r- 


Internal  Structure. 

The  Internal  Structure  and  the  Texture  oi 
Rocks  have  been  recently  divided,  and  treated  of 
separately  :  the  following  are  the  different  varie- 
ties of  structure. 

Laminar :  which  may  be  divided  into  the  lamel- 
lar, foliated  and  schistose. 

In  the  former  division  of  this  structure,  a  rock 
divides  more  or  less  easily  into  plates,  seldom  con- 
tinuous or  allowing  further  division. 

The  lamellae  are  not  necessarily  straight,  and 
occur  from  a  few  lines  to  many  yards  in  thickness. 
They  are  sometimes  divided  by  natural  joints,  and 
then  assume  a  prismatic  a  cuboid al  figure. 

There  is  a  large  and  a  small  lamellar  structure : 

the  former  is  seen  in  granite,  the  latter  in  horn- 
19 


134 

blende.    This  structure  occurs  in  masses  and  veins. 

The  foliated  structure  occurs  in  the  mixed  rocks 
only,  and  is  defined  to  be  "  rather  a  tendency 
to  split  into  parallel  lamina?,  or  an  appearance  of 
parallelism  in  the  disposition  of  the  integrant  mi- 
nerals, than  in  the  property  of  actual  splitting." 

Tne  lamina?  are  irregular,  and  often  curved  :  a& 
is  usually  seen  in  foliated  rocks.  They  are  sel- 
dom continuous  or  even;  when  they  are,  the 
structure  is  passing  into  the  schistose. 

The  schistose  structure  is  evinced  by  the  fisility 
of  the  rock  on  the  use  of  force  :  being  rarely  affect- 
ed by  the  weather ;  while  foliated  and  lamellar 
rocks  are. 

This  modification  of  structure  is  found  in  simple 
as  well  as  aggregate  rocks.  The  thickness  of  the 
laminae  is  inconsiderable ;  the  length  varies  from 
half  an  inch  to  several  yards.  They  are  sometimes 
even  and  smooth,  at  others  rough  and  nodular, 
They  are  not  necessarily  straight. 

This  structure  occurs  only  in  strata. 

The  schistose  sometimes  run  into  the  next  divi- 
sion of  structure. 

Fibrous  is  confined  to  argillite  and  limestone.  It 
is  sometimes  parellel,  straight  or  curved.  The 
fibres  sometimes  diverge,  presenting  a  ramified 
appearance. 


135 

Spheroidal  comprises  all  varieties  of  concretiona- 
ry structure.  The  concretions  may  be  spherical, 
touching  only  at  points,  the  interstices  being  filled. 
At  times,  by  compression,  they  become  ovate,  and 
assume  irregular  shapes.  Sometimes  they  have  a 
radiated  structure ;  and  sometimes  contain  a  nu- 
cleus. In  some  cases  this  structure  is  observable 
only  when  the  rock  is  weathered. 

The  size  of  the  concretions  seldom  exceeds  an 
inch  and  is  at  times  very  minute. 

In  some  cases  this  structure  is  confined  to  spots 
in  the  rock,  and  then  the  concretions  are  large 
and  irregular. 

Prismatic,  including  columnar  structures.  The 
common  prismatic  is  a  modification  of  the  large  la- 
minar, divided  transversely  by  natural  joints  :  be- 
ing cuboidal  or  quadrilateral,  seldom  having  a  less 
number  of  sides. 

By  the  action  of  weather,  or  by  partial  decom- 
position the  angles  are  often  rounded,  so  as  to  pre- 
sent a  spheroidal  concretionary  structure  :  which 
is  also  caused  by  the  desquamation  of  crusts. 

In  columnar  structure  there  is  no  limit  to  the 
number  of  sides,  and  the  length  is  much  more  than 
the  breadth.  In  such  instances  as  exhibit  a  very 
short  prism,  the  structure  becomes  tabular.  This 
structure  is  always  aggregated.  No  instance  having 
occurred  of  a  single  column. 


136 

The  prisms  are  often  seen  in  parallel  ranges 
forming  a  bed  for  some  distance ;  and  sometimes 
pass  imperceptibly  into  the  massive  rock.  When 
parallel  and  upright,  their  beauty  and  regularity  is 
remarkable,  and  has  given  eclat  to tfc  Fingals  Cave" 
in  the  island  of  Staflfa.  Parallelim  is  not  necessary ; 
since  they  are  sometimes  found  diverging  as  from  a 
centre;  occasionally  in  confused  heaps,  and  again 
dispersed  and  entangled,  as  it  were,  in  the  massive 
or  amorphous  variety.  Nor  are  columns  always 
straight ;  being  sometimes  much  bent  in  the  same 
direction,  or  in  contrary  directions,  or  mixed  with 
straight  ones. 

The  prismatic  structure  occurs  in  veins  as  well 
as  beds.  It  does  not  necessarily  exclude  the  small- 
er kinds  of  structure,  as  the  amygdaloidal  and  por- 
phyritic. 

The  size  of  prisms  varies  from  an  inch  or  less, 
in  diameter,  to  several  feet :  in  basalt  they  occur 
occasionally  9  feet  thick,  in  iron  stone  sometimes 
the  tenth  of  an  inch.  In  length  from  1  to  300  feet — 
or  perhaps  more.  They  occur  with  all  number  of 
sides  from  3  to  12. 

Prisms  are  usually  divided  by  irregular  joints 9 
destroying  the  appearance  of  continuity.  The  most 
perfect  and  numerous  joints  are  seen  in  the  most 
regular  columns.  Occasionally  they  are  so  frequent 


137 

as  to  produce  tabular  prisms.  The  surfaces  of 
these  joints  are  in  close  contact — and  may  be  plane 
or  concave  and  convex,  presenting  a  ball  and  sock- 
et joint. 

Veined,  comprises  all  those  veins  confined  to  one 
rock,  and  which  consist  of  the  same  substance  as  the 
matrix.  One  or  more  veins  may  be  found  separate, 
or  confused  in  the  mass— and  occasionally  the  same 
appearance  presented  by  the  veins  is  observable  in 
a  patch  or  spot  at  a  distance  from  it.  The  size  of 
such  veins  differs  from  half  an  inch  to  a  few  feet — 
both  in  length  and  breadth.  Their  hardness  usually 
resists  decomposition,  and  causes  them  to  be  raised 
above  the  surface.  Sometimes  they  are  discerni- 
ble on  the  fresh  fracture,  at  other  times  not  till  the 
matrix  is  in  part  worn  away.  They  often  intersect 
each  other,  exhibiting  a  reticulated  surface,  show- 
ing that  in  the  interior  of  the  rocks  laminae  cross 
each  other.  Trap  and  granite  are  more  frequent- 
ly veined  than  other  rocks. 

Cavernous.  When  in  the  last  mentioned  structure, 
the  intervening  walls  or  veins  no  longer  appear 
small,  but  constitute  the  greatest  portion,  it  passes 
into  the  cavernous,  which  is  seldom  seen  on  the 
fresh  fracture ;  but  frequently  when  the  surface  is 
partially  decomposed.  The  cells  vary  in  size, 
shape  and  frequency — and  are  often  filled  with 


138 

some  substance  different  from  the  constituents  of 
the  rock.  This  structure  is  often  seen  in  sand- 
stones and  limestones. 

•Amyvdaloidal  and  the  preceding  are  often  found 
in  the  same  rock  The  caverns  or  cells  are  filled 
with  different  mineral  substances,  appearing  to  be 
imbedded.  These  vary  in  size  and  shape. 

This  structure  is  mostly  confined  to  the  over- 
ly ing  family,  and  to  rocks  of  volcanic  origin. 

•Aggregate  evinces  a  composition  of  the  fragments 
of  different  rocks — -as  the  breccia*  and  conglom- 
erates and  sandstones.  The  parts  consist  of  one 
or  more  rocks,  with  quartz — united  sometimes  with, 
and  sometimes  without,  any  apparent  cement :  the 
size  varying  from  a  grain  to  several  feet.  The  frag- 
ments may  be  rounded  or  angular — sometimes,  but 
rarely,  both  are  found  in  the  same  mass. 

Granular,  also  called  crystalline,  exhibits  grains 
of  one  or  different  minerals  closely  aggregated,  as  if 
by  confused  crystallization,  usually  of  small  size. — 
It  is  difficult  to  be  distinguished  from  the  last  variety. 

Porphyritic,  where  crystals  of  one  or  more  minerals 
are  included  in  a  simple  or  compound  base.  The 
size  of  the  crystals  varies  from  a  mere  speck  to  an 
inch,  or  more.  When  the  crystals  disappear,  or 
the  base  is  coarse  granular,  the  structure  chang- 
es. It  is  connected  with  the  amygdaloidal. 


139 
Texture. 

Under  this  term  are  arranged  those  modifications 
in  which  the  mass  appears  homogeneous,  or  consist- 
ing of  parts  that  cannot  be  separated. 

It  is  in  this  way  distinguishable  from  structure, 
in  which  we  see  the  component  parts  more  or  less 
separated :  so  that  the  texture  is  in  fact  indica- 
tive of  the  structure.  In  mineralogy  the  term  is 
familiar.  It  is  not  seen,  except  the  rock  be  bro- 
ken; and  most  of  the  circumstances  arranged  under 
this  head  are  also  embraced  by  the  terms  fracture 
and  structure. 

Granular  does  not  denote  that  the  rock  may  be 
separated  into  grains :  but  is  applied  to  its  aspect. 
This  texture  is  not  always  the  same.  It  is  sandy 
or  arenacious,  or  is  flat.  The  appearance  may  be 
crystalline,  or  earthly.  It  passes  into  the  crystal- 
line, and  fibrous  and  scaly  textures. 

Bladed.  I  do  not  remember  to  have  seen  this 
texture.  It  occurs  in  hornblende  and  actynolite 
schists,  and  arises  from  the  interlacing  of  prisms, 
passing  from  the  granular  texture  to  the  fibrous. 

Fibrous,  arising  from  the  condensed  aggregation 
of  minute  irregular  prisms,  more  or  less  distinct. 

The  fibres  are  not  always  straight :  but  may  be 
curved,  or  radiating,  or  confused,  for  which  modi- 


140 

fications  several  names  have  been  given,  indi- 
cative of  the  arrangement. 

By  the  parallel  position  of  minute  scaly  or  gran- 
ular particles,  it  passes  into  the  scaly  texture. 

Scaly,  in  which  the  scales  may  be  parallel  or 
confused,  and  more  or  less  easily  separated. — 
Usually  the  scales  are  minute;  when  not,  this 
texture,  passes  into  the  small  lamellar  structure. 

Compact  texture  presents  no  appearance  of 
grains,  and  is  considered  as  precluding  all  the  pre- 
ceding modifications.  The  various  aspects  it  as- 
sumes belong  to  the  succeeding  character. 

Fracture. 

By  this  term  is  understood  the  appearance  of  a 
new  surface  of  a  rock,  upon  being  broken.  It  de- 
pends in  a  great  degree  upon  the  texture ;  the  small 
fracture  more  particularly.  There  are  several 
modifications  of  fracture. 

Even ;  in  which  the  surface  is  a  plane,  without,  or 
with  a  very  small  degree  of  curvature. 

Uneven :  in  which  the  planes  are  variously  in- 
clined, and  form  by  their  angles,  elevations  and 
depressions.  When  minutely  uneven,  with  the  ele- 
vations and  depressions  considerable,  it  become? 
granular,  and  forms  a  texture. 


141 

Conchoidal.  In  this  fracture  one  stitface  is  con- 
cave, and  the  other  convex,  to  a  greater  or  less 
extent,  and  frequently  marked  by  curved  lines, 
more  or  less  parallel. 

There  are  several  accidental  varieties  of  this 
fracture :  two  distinct  concavities  may  occur,  the 
smaller  within  the  larger,  or  there  may  be  several 
sm  dl  conchoidal  appearances  producing  an  undu- 
lating surface. 

These  three  varieties  maybe  united,  or  pass  into 
each  other.  They  may  also  be  united  with  some 
of  those  that  follow. 

Splintery,  is  produced  by  wedge  shaped  scales^ 
straight  or  curved,  of  which  the  thin  edges  are  more 
or  less  elevated,  and  occasionally  transparent. 

In  the  large  splintery  fracture,  the  scales  are  of 
considerable  breadth  in  proportion  to  their  thick- 
ness, and  are  flat  or  curved.  It  occurs  frequently 
in  connection  with  the  choncoidal. 

In  the  small,  when  the  splinters  are  very  narrow, 
they  may  exhibit  something  of  a  fibrous  aspect  :--* 
when  thick  and  short,  something  of  a  granular  ap- 
pearance. 

Hackly  fracture  is  rare— occurring  only  in  some 
schistose  rocks.    It  is  known  by  the  extreme  sharp- 
20 


142 

ness  of  the  protruding  parts.    It  may  be  well  seen, 
by  the  transverse  fracture  of  aggregated  fibres. 

The  granular,  fibrous,  and  scaly  fractures  are  si- 
milar to  the  textures  with  those  names. 

Hardness. 

This  character  of  rocks  is  so  various  that  it  is 
impossible  accurately  to  describe  it.  It  ranges 
from  the  hardness  of  quartz  to  that  of  chalk. — 
These  extremes  are  well  known,  and  the  interme- 
diate varieties  must  be  tested  by  some  equally 
known  standard;  as  the  comparative  ease  with 
which  they  are  scratched  by  the  point  of  a  knife, 
or  the  finger  nail.  To  strike  fire  with  steel  is  an 
inadequate  test,  as  that  depends  often  on  the  form 
of  the  fragments,  and  is  frequently  produced  by 
the  intermixture  of  quartz. 

Colour. 

Among  the  external  characters  of  rocks  none  va- 
ries so  much  as  colour — and  still  it  has  often  been 
insisted  upon  as  characteristic. 

In  some  instances  the  colour  is  well  defined,  as 
in  limestone,  serpentine,  &,c. — but  in  many  cases 
the  tints  are  broken ;  and  those  comprised  un- 
der the  ceaseless  changes  of  grey  are  the  most  pre- 
dominant. Different  colors  are  sometimes  present 


143 

in  the  same  compound  rock :  and  occasionally  de- 
pending on  the  colour  of  several  substances  united 
in  the  mass. 

Iron,  in  some  of  its  conditions,  is  usually  the  agent 
by  which  rocks  are  coloured. 

The  endless  variety  of  colours  affords  a  name 
for  every  shade  which  may  be  found  in  rocks — but 
as  the  colour  of  the  same  rock  frequently  changes, 
this  character  does  not  belong  to  the  permanent 
catalogue.  Still  it  merits  attention,  as  frequently 
forming  species  which  in  economical  purposes  are 
highly  prized — as  in  marbles. 

Mr.  Symes  of  Edinbugh  has  published  a  work  on 
colours  wich  deserves  notice  by  those  who  wish 
more  particularly  to  attend  to  this  character  of 
rocks  or  minerals. 

Frangibility. 

This  character  is  very  various,  as  some  rocks 
yield  to  a  slight  blow,  and  others  resist  a  great 
force.  It  depends  in  some  measure  upon  the  wa- 
ter the  rock  contains,  and  the  direction  given  to 
the  applied  force.  When  the  interior  of  a  mass  is 
broken  it  is  often  frangible  forthe  time,  but  becomes 
tough  by  exposure.  To  convey  the  proper  idea 
of  the  frangibility  of  a  rock,  it  must  be  compared  to 
some  familiar  object, 


144 

Lustre. 

This  character  varies  from  that  of  plubmago, 
the  highest  degree  of  lustre  found  in  rocks,  to  that 
of  chalk,  which  is  dull  and  earthy;  in  fact  to  the 
total  want  of  lustre.  The  shades  are  not  very  nu- 
merous, and  are  often  indefinite.  The  standard 
however  being  fixed,  a  reference  is  easy  and  suffi- 
ciently definite  for  common  use  ;  thus  there  are  six 
degrees  of  lustre  referred  to,  viz :  the  plumbaginous, 
the  silky,  the  resinous,  the  vitreous,  the  flinty,  and 
the  waxy.  The  latter  offers  a  double  standard  of 
comparison,  in  its  lustre,  after  having  been  melted, 
and  in  the  fracture  it  presents  when  broken. 

Transparency. 

The  thin  edge  of  a  splinter  of  rock  may  trans- 
mit a  small  degree  of  light,  and  be  translucent, 
but  although  transparency  belongs  to  several  min- 
erals, it  does  not  properly  appertain  to  rocks. 

Specific  gravity. 

This  character  is  of  little  or  no  value  in  the  com- 
parison of  rocks.     When  the  weight  of  a  rock  is 
Mentioned,  the  specific  gravity  ascertained  in  the 
usual  mode,. should  be  noted,  so  as  to  convey  a  dr 
finite  idea. 


145 

Jiction  of  Adds. 

In  discriminating  certain  limestones,  the  action 
of  dilute  nitrous  or  muriatic  acid,  by  the  extrication 
of  carbonic  acid  gas,  is  a  convenient  standard. 


LECTURE  V. 

Primary  Rocks — Granite — Gneiss — Mica  Slate- — 
Jlrgillite — Serpentine — Limestone — Quartz  rock — 
Chlorite  Schist — Takose  Schist — Hornblende  rocks — 
Jlctynolite  Schist — Porphyry — Syenite.  Identity  of  for- 
mations— Isochronism — Alternation — Loxodromism-— 
Character  of  Primary  Soils. 

All  geologists  agree  in  assigning  an  extreme  date 
to  GRANITE — and  it  is  usually  placed  as  the  first,  or 
lowest  of  primary,  and  therefore  of  all  rocks.  It  is 
considered  as  unstratified :  is  one  of  the  most 
abundant,  and  most  useful  of  rocks.  It  derives  its 
name  from  its  usual  granular  appearance. 

It  is  placed  in  irregular  masses  beneath  all  other 
strata,  occasionally  sending  veins  into  the  adjacent 
rocks.  It  seldom  presents  a  definite  form :  but  is 
occasionally  so  divided  by  fissures  as  to  make  it 
bear  some  analogy  to  stratification.  When  these 
crevices  or  fissures  are  so  placed  as  to  produce  a 
prismatic  figure,  the  angles  are  sometimes  rounded 
off,  and  an  irregular  spheroid  is  the  result. 

Granite  sometimes  presented  a  minute,  but  irre~ 
gular  prismatic  structure,  independant  of  the  above. 


147 

It  is  also  occasionally  minutely  laminar,  or  exib- 
liates  in  crusts,  that  are  sometimes  concentric, 
sometimes  flat ;  in  some  cases  appearing  the  result 
of  a  concretionary  structure  in  the  rocks  ;  in  others 
as  the  consequence  of  atmospheric  action. 

The  component  parts  of  Granite  are  Quartz 
Mica  and  Felspar:  of  these  three  substances  I  shall 
give  a  brief  notice — not  intending  it  however  as  a 
precedent  to  be  followed  in  describing  the  other 
rocks :  but  to  show  the  necessity  for  an  intimate 
acquaintance  with  mineralogy,  previous  to  com- 
mencing the  study  of  Geology.  It  will  also  show 
the  connection  between  mineralogy  and  che- 
mistry. 

Quartz  is  a  siliceous  earth  very  plentifully  distri- 
buted. It  is  frequently  limpid,  but  occurs  of  all  the 
tints  of  yellow,  green,  and  red,  derived  from  me- 
tallic agents. 

Its  usual  form  is  a  6  sided  prism,  terminated  by 
6  sided  pyramids,  more  or  less  regular.  Not  un- 
frequently  it  has  metallic  fibres  running  through  it, 
and  then  becoming  more  valuable,  is  cut  and  set  as 
an  ornament.  It  has  a  great  comparative  hardness? 
scratches  and  cuts  glass ;  and  is  not  scratched  by 
steel.  Before  the  compound  blowpipe  it  melts  in- 
stantly. 


Quartz  is  the  purest  variety  of  siliceous  earth, 
containing  about  69,  and  some  even  96  per  cent,  of 
pure  silex.  Rock  crystal  is  quartz.  It  forms  a  large 
proportion  in  the  composition  of  calcedony,  agates, 
flints,  jaspers  &,c.  It  is  also  a  constituent  in  many 
gems :  Opal  and  Cairngoram  are  nearly  pure  quartz. 
Topaz,  Hyacinth,  schorl,  and  tourmaline,  aven- 
turine,  emerald,  beryl  and  garnet  all  contain  large 
portions  of  this  earth.  It  is  an  important  article  in  the 
arts ;  is  used  in  the  manufacture  of  glass,  is  an  in- 
gredient in  the  preparation  of  porcelain,  and  earth- 
enware, and  of  smalt.  It  is  used  in  the  form  of 
sand,  in  all  mortars — and  in  agriculture,  for  the 
improvement  of  certain  soils. 

Felspar  is  also  widely  distributed.  It  is  a  com- 
pound substance,  in  which  silliceous  earth  is  in  the 
greatest  proportion,  frequently  coloured  by  oxide 
of  iron.  The  following  is  the  composition  accord- 
ing to 

CHENEVIX.  BRANDE. 


Silex       w-#«»T*:-  64. 
Alumine       -  24. 

Potash         .     *'-• 
Lime      ...     -       6.  25 
Oxide  of  iron  •    -      2. 

86.  25 


•     - 


v 

*        >i^ 

149 

It  is  softer  than  quartz,  and  easily  fusible.  It  is 
usually  red,  grey,  or  white,  with  varieties.  The 
crystals  are  4  and  6  sided  prisms,  bevelled,  the 
primitive  form  being  a  slightly  obtuse  rhomboid. 

The  extreme  beauty  of  some  varieties  of  feldspar 
has  occasioned  its  use  in  ornamental  jewelry.  Per- 
sia, Arabia  and  Ceylon  furnish  the  green  variety, 
which  is  much  prized.  On  the  coast  of  Labrador 
it  occurs  very  beautiful  To  Dr.  Bigsby,  we  are 
indebted  for  the  knowledge  of  an  extensive  locali- 
ty in  the  vicinity  of  Lake  Huron. 

Under  the  name  of  Petunze,  it  is  used  in  the 
manufactory  of  porcelain — It  was  first  employed  by 
the  Chinese  :— is  now  extensively  used  by  the 
French  at  the  celebrated  Sevres,  under  the  name 
of  decomposed  feldspar — and  also  by  the  English, 
who  have  a  valuable  locality  of  it  in  Cornwall.  It 
retains  its  whiteness  remarkably  pure,  from  there 
being  no  iron  in  its  composition.  By  analysis 
it  yielded  according  to 

VAU^UELIN.  WEDGEWOOB. 


Silex     -     ---     74. 
Alumine    -  .  ?  i  *     14.  05 
-     -  5.  06 


Lime 


95. 


---.----     20. 
60. 

Loss  and  moisture     -    20. 

100 


21 


150 

The  other  ingredient  usually  noticed  is  Mica — 
a  compound  mineral,  consisting  of  the  earths,  silex, 
alumine,  and  magnesia,  tinged  with  iron.  Its  color 
is  grey,  passing  into  brown  and  black  —very  rare- 
ly, green  and  rose  coloured.  It  is  easily  fusible 
by  the  blowpipe.  Its  crystal  is  a  rhomboidal  prism; 
•  < — texture  lamellar;  It  is  easily  divisible  into  ex- 
tremely thin  plates.  It  is  scratched  by  the  finger 
nail.  It  yields  by  analysis — 

Silex  >;rf! 

Alumine    - 

Potash     :--K 

Ox  of  iron 

Maganese  - 

Water 

97.  25 

In  Siberia  and  Russia  this  mineral  is  reguarly 
mined  and  is  an  article  of  commerce,  under  the 
name  of  Muscovy  glass.  Its  flexibility  has  caused 
its  use  instead  of  glass,  in  the  Russian  ships  of  war 
as  it  is  not  liable  to  breakage  by  the  discharge  of 

guns.     Considerable   quantities  are   exported  : 

200  puds  being  yearly  sent  to  Lubec,  and  a  large 
quantity  to  England  and  Ireland. 

These  three  substances,  quartz,  felspar  and  mi- 
ca,  are  usually  considered  as  the  component  parts 
of  Granite,  and  so  they  are,  generally.  But  it  is 
a  distinction  not  sufficiently  correct  for  geological 


151 

purposes.  For  instance,  in  a  small  space,  ei- 
ther the  former  or  latter  of  these  may  disappear 
— and  the  latter  invariably  does  in  graphic  granite. 
Hornblende  is  sometimes  a  constituent,  with  all  the 
other  three — and  sometimes  usurps  the  place  of 
mica  insensibly,  and  forms  a  compound  of  quartz, 
felspar  and  hornblende;  which  is  then  called  Sye- 
nite. 

Granite  therefore  consits  of  quartz,  felspar,  mica 
and  hornblende  in  different  proportions.  Other 
minerals  too  sometimes  enter  into  the  compound — 
viz :  actynolite,  chlorite,  talc,  compact  felspar  and 
steatite. 

The  size  of  the  grains  of  granite  varies  from  a 
minute  speck  to  several  feet  in  length.  It  is  so  fine 
as  scarcely  to  be  distinguished  from  sandstone,  and 
so  coarse  as  to  be  almost  a  conglomerate ;  and  these 
gradations  may  occur  almost  imperceptible  in  a 
short  distance.  In  one  locality  alone,  Corsica,  it 
is  orbicular. 

The  proportions  of  the  ingredients  vary  much : 
generally  speaking  felspar  is  the  most,  and  mica 
the  least  abundant.  One  of  them,  the  quartz 
particularly,  may  be  altogether  wanting — >and  in 
some  cases  one  of  them  may  form  large  masses  or 
beds. 


152 

The  colours  of  granite  are  of  almost  every  shade 
—that  of  the  felspar,  as  it  is  the  most  variable,  and 
abundant,  usually  regulates  the  general  tint  of  the 
rock — Dark  red,yeilow — and  all  varieties  of  gray 
• — to  black  and  green. 

Quartz  is  next  in  quantity,  and  its  whiteness  as- 
sists in  forming  the  general  hue  of  the  granite — it  is 
sometimes  grey,  smoky,  and  black. 

Mica  being  either  white,  or  brownish,  or  blackish, 
modifies  the  colors  of  the  compound — causing  grey 
and  black  tints,  which  may  also  arise  from  horn- 
blende. This  mineral  however,  being  almost  con- 
stantly blackish  or  dark  green,  contributes  in  pro- 
portion to  its  quantity. 

Sometimes  each  of  the  minerals  may  have  a  dif- 
ferent color — and  occasionally,  though  rarely, 
all  may  be  crystallised. 

The  size  and  position  of  the  different  ingredi- 
ents have  given  rise  to  several  varieties. 

Graphic  Granite,  is  composed  chiefly  of  quartz 
and  felspar,  the  latter  forming  a  broad  base,  in 
which  the  other  is  imbedded:  when  broken  across 
the  rows  of  quartz,  it  resembles  written  characters, 
and  hence  the  name.  Its  decomposition  furnishes 
porcelain  clay — Kaolin.  It  is  found  on  our  own 
Island. 


153 

Globular  Granite  is  composed  of  distinct  concre- 
tions. The  most  beautiful  is  from  Corsica  and  Ar- 
ran :  not  found  in  this  country. 

Porphyritic  Granite  is  so  called  from  the  fineness 
of  its  texture,  which  contains  large  crystals  of 
felspar. 

Protogine  arises  from  the  substitution  of  talc,  stea- 
tite or  chlorite  for  mica — al  ogether  or  partially. 

Owing  to  the  want  of  uniformity  in  the  propor- 
tions of  the  compound,  granite  has  received  new 
and  various  names  :  thus  when  only  two  of  the  usual 
constituents  are  present,  imbedding  some  othersim- 
ple  mineral,  it  was  called  a  Granitic  aggregate. — 
Kirwan  introduced  specific  names  for  these  aggre- 
gates ;  they  have  however  been  abolished. 

Granite,  1  have  said  is  the  oldest  rock.  It  oc- 
curs in  mountain  masses—  and  apparently,  in  strata, 
in  veins,  and  in  beds.  It  does  not  seem  to  have  been 
deposited  at  the  same  time.  It  forms  the  highest 
as  well  as  the  lowest  points  that  have  been  exam- 
ined, and  constitutes  the  summit  and  central  part 
of  the  highest  mountains.  In  some  instances  it  is 
entirely  hidden  by  the  rocks  superimposed. — 
When  it  forms  the  tops  of  mountains,  the  summit 
presents  a  ragged  and  pointed  peak.  The  high- 
est locality  in  the  world  where  granite  has  been 
been  seen — indeed  tue  highest  rock  that  has  been 


154 

examined  is  on  the  summit  of  Mount  Blanc,  or  ra- 
rather  a  few  feet  below  the  summit,  whence  I 
brought  these  specimens  in  1819:  they  are  of  the 
variety  protogine. 

Mount  Blanc  in  Savoy  is  the  loftiest  mountain 
in  Europe,  rearing  its  majestic  head  15,H8u  feet 
above  the  level  of  the  sea:  being  three  times  high- 
er than  the  highest  point  in  the  United  States. 

The  relative  height  of  Mount  Blanc  is  greater 
than  that  of  Chimborazo,  since  it  rises  1 1,530  feet 
above  the  valley  of  Chamouny,  while  Chimborazo 
is  elevated  but  1 1 ,2  >2  feet  above  the  valley  of  Ta- 
pia,  making  a  difference  of  300  feet  relative  height. 
The  upper  f  of  this  mountain  of  granite  are  within 
the  confines  of  perpetual  snow.  Rising  above  the 
clouds,  its  summit  enjoys  the  golden  splendour  of 
the  sun,  but  is  cheered  by  no  plant  nor  animal. 

But  seven  times  since  its  creation  had  the  summit 
been  trodden  by  the  foot  of  man  previous  to  18 1 9, 
when  I  succeeded,  in  company  with  Dr  Howard, 
of  Baltimore,  and  nine  guides,  in  an  attempt  to 
reach  the  highest  point  of  Europe.  After  a  jour- 
ney of  ^3  hours,  45  of  which  were  passed  in  the 
region  of  eternal  ice,  we  returned  to  the  beautiful 
vale  of  rhamony.  As  our  perilous  and  fatigueing 
expedition,  unfortunately  added  no  scientific  ob- 


155 

serrations  to  those  made  by  Saussure  and  others, 
we  abstained  from  obtruding  on  the  public  the  re- 
cital of  our  dangers  or  sufferings. 

Many  beautiful  and  valuable   minerals  occur  in 
granite,  as 


Garnet 

Apatite 

Actynolite 

Cyanite 

Pmite 

Gabbronite 

Spodumene 

Idocrase 

W  erne  rite 

Corundum 
Beryl 

Anthophyllite 
Andalusite 

Pyrites 
Oxidulous  iron 

Emerald 

Stilbite 

Sphene 

Topaz 

Jade 

Oxide  of  Tin 

Chrysoberyl 

Fetstein 

Lapes  Lazuli 

Epidote 

Tourmaline 

Graphite 

Zi  rcon 

Schorl 

Fluor  spar 

Tremolite 

Many  metals  are  found  in  granite— either  in 
or  in  veins,  or  disseminated  through  the  mass — viz : 
Tin,  iron,  tungsten  molybdena,  uranium,  titanium, 
manganese,  arsenic,  cobalt,  zinc,  lead,  bismuth, 
copper,  silver  and  gold. 

Granite  contains  neither  coal,  gypsum  or  salt. 

It  is  the  most  durable  of  all  rocks,  and,  as  it 
can  be  worked  and  polished,  it  is  well  suited  for 
architecture.  The  columns  of  the  portico  of  the 
Pantheon,  the  Ionic  columns  of  the  temple  of  Con- 
cord in  the  Forum  Romanum,  and  many  others,  as 
well  as  the  obelisks,  in  Rome,  are  of  granite 
brought  from  Egypt. 


GNEISS  which  is  generally  placed  second  on  the 
list  of  rocks,  is  also  a  compound  of  quartz,  felspar 
and  mica.  Its  structure  is  usually  slaty,  while 
granite  is  granular  and  this  is  supposed  to  constitute 
the  sole  or  surely  the  chief  difference.  It  contains 
more  mica  and  less  feldspar  than  granite.  The 
mica  forms  fluillets  or  small  leaves  between  the 
quartz  and  felspar — and  when  Gneiss  is  divided,  it 
facilitates  the  operation  hy  its  want  of  adhesion, 
and  shows  itself  in  more  abundance. 

The  composition  always,  and  the  texture  often 
assimilates  this  rock  to  granite.  The  following 
are  the  points  of  Distinction.  Crystals  of  mica  and 
hornblende  in  granite  are  mixed  with  the  utmost 
irregularity,  but  they  preserve  a  paralell  in  Gneiss, 
giving  to  it  the  foliated  aspect.  To  describe  the 
modes  >f  aggregation  would  be  to  repeat  what  has 
been  said  of  Granite. 

In  some  countries  it  is  the  most  abundant  of  the 
primary  rocks,  forming  whole  districts  arid  consti- 
tuting high  mountains  of  one  entire  mass.  Its 
strata  are  of  various  dimensions,  generally  thick, 
unless  alternating  with  quartz  rock,  mica  slate,  or 
hornblende  schist,  when  it  becomes  thin:  particu- 
larly when  alternating  with  latter  stratum, 


157 

Gneiss  is  not  always  perceptibly  stratified :  when 
intersected  by  veins  of  granite,  it  has  many  resem- 
blances to  an  irregular  granitic  mass  :  when  the 
grains  are  very  coarse,  the  resemblance  to  granite 
is  so  strong  as  to  confound  the  student.  This  is 
more  especially  the  case  when  the  veins  of  granite, 
run  parallel  with  the  laminae. 

When  there  is  no  intermixture  of  granite  veins 
the  stratification  of  gneiss  is  very  regular. 

Gneiss  is  subject  to  contortions  of  all  magni- 
tudes. It  offers  so  many  varieties  of  structure  as 
not  to  allow  of  specific  descriptions  :  the  granitic, 
the  schistose  and  the  laminar  are  usually  noticed. 

Where  gneiss  and  granite  are  in  immediate  con- 
tact, the  transition  is  scarcely  perceptible  by  the 
variety,  magnitude  and  mixture  of  the  particles, 
until  at  length  the  fissile  or  foliated  structure  be- 
comes apparent. 

It  is  the  next  rock  to  granite,  and  occurs  resting 
or  lying  upon  it.  When  they  are  both  seen  in  the 
same  mountain,  its  ledge  is  always  the  lower  of  the 
two.  Mountains  of  Gneiss  are  seldom  so  steep  as 
those  of  granite,  and  the  summits  are  not  quite  so 
peaked. 

Gneiss,  like  granite,  has  been  formed  at  different 
times — and  is  found  alternating  with  granite,  with 

serpentine,  and  with  mica  slate. 

22 


158 

The  colour  of  gneiss  varies  in  the  same  manner, 
and  from  the  same  cause,  as  that  of  granite. 

It  is  the  repository  of  many  minerals — of  which 
the  most  usual  are 


Sapphire, 
Ruby 
Emerald 
Beryl 
Cats  eye 
Zircon 
Chrysoberyl 

Epidote 
Garnet 
Actinolite 
Quartz 
Feldspar 
Hornblende 
Fluor  Spar 

Carb.  of  Lime 
Tourmaline 
Melanite 
Idocrase 
Oxydulous  iron 
Cinnamon  Stone 

It  also  contains  beds  of  limestone,  hornblende* 
porphyry,  and  anthracite. 

It  is  the  most  metalliferous  of  all  rocks — contain- 
ing all  those  found  in  the  preceding  in  greater 
quantity — In  Norway,  Sweden,  and  Saxony,  the 
most  important  mines  are  in  this  rock. 

It  is  used  for  the  same  purposes  as  granite,  but 
is  neither  so  durable,  nor  so  easily  cut  and  polished. 

Like  its  predecessors,  Gneiss  becomes  irregular 
in  composition ;  varying  from  the  older  kinds,  in 
which  the  component  parts  may  be  said  to  be  dis- 
posed into  distinct  curvilinear  layers,  to  the  newest 
varieties,  where  the  composition  becomes  more 
diffused,  and  the  layers  thinner,  the  structure  per- 
fectly slaty,  and  the  whole  mass  more  fissile,  when 
it  passes  into  the  third  primitive  rock. 


159 

MICA  SLATE  :  composed  of  quartz  and  mica, 
variously  mixed,  the  latter  usually  predominating. 
It  differs  from  Gneiss  principally  in  wanting  feld- 
spar as  an  ingredient — and  as  the  same  ingredients 
constitute  Quartz  rock,  it  passes  into  that  also. 
It  also  passes  easily  into  Chlorite  Slate  and  Tal- 
cose  Slate,  and  occasionally  even  into  Argillace- 
ous Slate,  so  much  is  its  character  sometimes  mo- 
dified by  the  admission  of  these  minerals.  The 
colour  is  usally  grey,  derived  from  the  shade 
of  the  mica,  as  the  quartz  is  almost  always  devoid 
of  color.  It  may  be  altered  by  the  admission  of 
foreign  substances  into  its  composition.  It  is  bril- 
liant— but  easily  decomposes.  The  older  varieties 
sometimes  contain  felspar. 

Like  other  primitive  rocks,  it  appears  to  have 
been  formed  at  different  periods. 

The  strata  are  sometimes  very  thick,  so  as  al- 
most to  seem  unstratified.  It  is  more  slaty  than 
gneiss,  and  the  layers  not  always  straight — often 
flexed  into  contortions,  sometimes  without  affecting 
the  stratum.  It  is  occasionally  split  into  plates 
or  slates.  It  is  not  decided  if  the  laminar  struct- 
ure is  or  is  not  parallel  to  the  plane  of  stratifica- 
tion. 


160 


The  position  of  this  rock  varies — as  it  alter- 
nates with  granite,  gneiss  and  greenstone  slate,  in- 
deed sometimes  with  argillite  and  limestone.  Its 
usual  place  is  on  gneiss  covering  granite.  It  gen- 
erally forms  large  tracts  of  countries,  and  elevated 
mountains,  seldom  high  cliffs ;  the  hills  are  round- 
ded  at  the  summit,  and  are  in  long  and  beautiful 
ridges,  separated  by  moderate  vallies. 

It  is  remarked  that  this  rock  supplies  the  great- 
est quanties  of  crystallised  minerals — among  these 
are. 


Garnet 
Tourmaline 
Beryl 
Schorl 
Emerald 
Corundum 

Actynolite 
Epidote 
Andalusite 
Kyanite 
Phrenite 
Apatite 

P  ynite 
Oxydulous  iron 
Pyrites 
Staurotide 

It  sometimes  contains  beds  of  limestone,  ser- 
pentine, hornblende,  quartz,  &c. 

It  abounds  in  ores,  in  beds  and  veins,  more 
particularly  the  latter.  The  mines  of  Saxo- 
ny, Bohemia,  Hungary,  of  Delicarlia  and  Fahlun 
are  in  mica  slate. 

It  will  have  been  observed  that  mica  slate  and 
gneiss  are  nearly  allied  to  granite,  and  it  was  for- 
merly supposed  that  the  three  constituted  the  pri- 
mary class,  and  formed  the  primitive  ridges  of  coun- 
tries. I  have  mentioned  they  are  the  oldest  rock 


161 

and  form  the  highest  mountains.  They  are  widely 
distributed.  No  country  is  without  them,  though 
they  may  not  always  predominate. 

Where  the  laminae  allow  mica  slate  to  split  into 
large  tables,  it  is  us.eful  for  fences  and  for  many 
domestic  purposes. 

The  origin  of  granite  has  been  a  subject  of  warm 
discussion  to  those  geologists  who  regard  theory 
as  the  most  important  part  of  the  study — and  it 
has  received  different  explanations  from  the  differ- 
ent schools. 

The  Wernerians  regard  it  as  a  deposition 
from  aqueous  solution,  which  was  followed  by  the* 
other  rocks  of  the  same  class.  They  account  for 
granitic  veins  by  a  new  deposition  entering  crevi- 
ces and  fissures  of  the  original  strata. 

These  granite  veins  are  supposed  by  the  Hut- 
tonians,  on  the  contrary,  to  have  been  elevated 
by  some  power  below;  so  that  granite  is  the 
latest,  instead  of  the  earliest  rock,  has  been  con- 
solidated by  heat,  after  the  other  depositions 
were  made,  and  forced  up  so  as  to  be  elevated, 
with  all  the  other  strata  resting  upon  it.  to  an  in- 
inclined  and  even  vertical  position. 

This  explanation  does  not  agree  with  the  local- 
ity of  many  veins  that  can  not  be  traced  to  any  or- 
iginal mass  or  mountain— of  which  kind  many 
exist. 


162 

The  elevating  by  these  means  of  such  immense 
masses  of  granite  as  mount  Blanc  and  Chimborazo 
appear  scarcely  credible. 

As  Geology  became  a  subject  of  study  and  at- 
tention, it  was  found  that  the  three  rocks  already 
mentioned,  by  no  means  constituted  even  the 
greater  number  of  the  primary  class.  The  most 
important  addition  was  Argillaceous  Schist  or 
ARGILLITE:  important  for  many  reasons.  It  was  ori- 
ginally considered  as  appertaining  to  the  next  class 
of  rocks,  and  by  being  introduced  here  blends  the 
Primary  and  Transition — as  even  those  sections 
of  Argillite  which  are  termed  primitive  are  allowed 
to  pass  imperceptibly  into  the  transition.  On  this 
account  the  arrangement  of  Macculloch  seems 
highly  proper — and  I  shall  follow  him  in  placing 
under  this  head  "  all  those  schistose  argillaceous 
rocks,  of  the  primary  class,  (in  which  he  includes 
the  old  transition,)  however  differing  in  texture  ; 
thus  comprising  the  clay  slate  and  the  gray  wacke 
of  some  geologists."  His  reasons  are  sound,  so  far 
as  my  observation  or  reflection  goes. 

In  all  cases,  the  coarser   and  finer  varieties  of 
this  rock  occur   as   parts  of  one  series,  however 
the  one  or  the  other  variety  may  predominate  in 
particular  instances.     If  fine  beds  or  strata  are 
found  without  the  coarser,  or  if  the  later  are  found 


163 

without  the  finer,  it  offers  no  greater  reason  for 
their  separation  than  is  offered  for  a  similar  division 
of  gneiss  or  mica  slate  by  its  coarse  or  fine  textures. 
These  textures  too  occassionally  present  them- 
selves in  the  same  bed,  either  laterally  or  trans- 
versely. Moreover,  in  the  case  of  sandstone  this 
arrangement  is  adopted  for  similar  reasons,  no  dis- 
tinction being  made  between  the  fine  and  coarse 
varieties,  although  the  differences  of  conglomerates 
and  fine  sandstones  are  much  greater  than  is  ever 
met  in  Argillite.  And  why  should  not  strata,  mecha- 
nically recomposed,  be  found  among  the  primary, 
as  well  as  among  other  rocks. 

The  only  differences  that  have  ever  been  offered 
between  the  older  and  newer  varieties  of  this  rock, 
are  negative.  Such  as  the  absence  of  nodules  or 
compact  limestone,  in  the  former;  the  want  of 
chiastolite,  of  numerous  beds  of  greenstone,  of 
alum  slate  and  drawing  slate — and  even  these 
characters  are  so  dubious  that  the  most  experi- 
enced geologist  may  be  at  a  loss,  as  Argillite  fre- 
quently shows  all  varieties  in  a  small  space. 

The  essential  components  of  Argillite  are  the 
peculiar  indurated  clay  which  alone  forms  all  the 
simple  varieties,  with  mica  and  quartz — The  coarse 
varieties,  or  greywackes,  contain  also  primitive 
fragments :  felspar  is  sometimes  found  in  it,  giving  it. 


164 

a  porphyritic  appearance.  These  circumstances 
produce  different  kinds  of  texture :  the  finer  is 
compact  and  uniform :  other  varieties  occur  from 
the  mixture  of  sand,  gravel  and  mica.  In  the  old- 
er kinds,  the  mica  is  in  large  scales  and  assimilates 
it  to  mica  slate,  while  in  the  newer  the  mica  be- 
comes very  small  and  fine.  In  the  compact  varie- 
ties as  hone  slates  &c.  the  union  of  parts  is  too 
firm  to  be  a  mere  mechanical  adhesion :  but  gene- 
rally indurated  clay  is  the  cement. 

It  passes  into  siliceous  schist  and  into  sand- 
stone. 

Argillite  sometimes  composes  whole  coun- 
tries, but  is  occasionally  only  in  small  quan- 
tities, alternating  with  other  rocks  in  a  very  curi- 
ous way. 

On  this  continent  it  is  found  supporting  im- 
mense countries,  as  all  the  table  land  of  St.  Fee 
de  Bogota — in  Peru  it  rests  immediately  on  an- 
cient granite.  Indeed  the  gradations  are  insen- 
sible of  granite,  gneiss,  mica  slate  and  argillite 

Thus  a  large  country  exhibits  gneiss  constantly 
alternating  between  granite  and  mica  slate :  and 
mica  slate  between  granite  and  clay  slate,  whence 
some  geologists  have  been  desirous  of  joining  them! 
as  one  formation :  in  the  same  manner  that  syenitei 
and  serpentine  pass  into  that  greenstone  called? 


165 

transition.  In  Cornwall  it  rests  near  to  granite 

In  England  it  occupies  large  tracts,  and  is  followed 
in  order  by  the  secondary  rocks. 

Although  it  may  be  difficult  to  trace  the  outline 
of  the  beds,  the  stratafication  of  argillite  is  not  dis- 
puted. In  large  tracts  it  is  frequently  of  immense 
thickness;  but  in  alternations  it  becomes  very  thin, 
in  the  same  mariner  as  micaceous  schist:  and  in  the 
same  way  too  the  strata  are  liable  to  contortions* 
but  seldom  the  rock  itself! 

The  schistose  structure  of  this  rock  renders  it 
valuable  for  many  purposes,  since  it  can  be  split 
into  lamina  of  almost  any  thickness,  particularly 
the  finer  varieties ;  though  often  the  graywacke 
schists  are  divisible  to  the  same  extent.  This  ten- 
dency is  not  necessarily,  though  it  is  generally 
parallel  to  the  plane  of  stratafication :  it  is  some- 
times oblique,  but  never  in  the  secondary  slates. — 
The  finer  varieties  present  sometimes  a  fibrous 
structure. 

Natural  joints  are  sometimes  transverse  or  ob- 
lique to  the  plane  of  stratafication,  forming  rhom- 
boidal  or  prismatic  figures,  more  or  less  perfect. 
Most  frequently  the  intersections  are  made  by 
minute  and  numerous  veins  of  quartz  or  calcareous 

23 


166 

spar,  which  in  some  rare  cases  follow  the  contor- 
tions of  the  schist. 

The  following  minerals  occur  in  this  rock. 


Garnet 
Epidote 
Topaz 
Opal 
Cyanite 
Chloiite 

Wavellite 
Staurotide 
Andalusite 
Chiastolite 
Brown  spar 
Calc.  spar 

Lazulite 
Tremolite 
Stilbite 
Oxydulous  iron 
Pyrites 

Argillite  contains  numerous  ores — the  hills  of 
Lima  and  Potosi,  rich  in  metals,  are  of  this  rock — 
The  copper  and  tin  mines  of  Cornwall  are  in  argil- 
lite. 

It  contains  beds  of  graphic  and  chlorite  slates,  of 
talc,  hornblende,  greenstone,  novaculite. 

It  has  a  few  organic  remains :  which  offer  the 
only  strong  reason  why  this  rock  should  not  be 
classed  among  the  prim.ary 

It  is  abundant  in  this  state.  Large  quantities  of 
it  are  annually  brought' from  Rensselaer  county  to 
Albany  and  to  this  city.  In  the  counties  of  Ulster 
and  Dutchess  it  occurs  of  such  quality  as  to  be  wor- 
ked advantageously. 

Pennsylvania  possesses  it  in  Wayne  county,  in 
Lancaster  and  in  York,  extending  into  Maryland. 
These  quarries  yield  annually  about  1600  tons — 
worth  22  Dollars  a  ton. 

It  occurs  near  New  Haven  in  Connecticut  and  is 
extensively  quarried  at  Charlestown,  Mass. 


167 

It  has  been  traced  by  Dr.  James  and  Mr.  Eaton 
about  30  miles  on  the  Hudson.  In  the  United 
States  it  has  an  extent  of  about  400  miles  North 
and  South. 

The  acclivities  of  Argillite  are  not  very  steep — 
and  the  soil  yielded  by  its  decomposition  is  better 
than  what  is  generally  afforded  by  the  primary 
rocks. 

These  four  rocks  form  the  great  divisions  of  the 
primary  class-but  do  not  constitute  it,  as  there  are 
many  other  important  members  of  this  series,  which 
were  formerly  treated  of  as  subordinate  beds. — 
Divisions  in  all  branches  of  science  are  readily 
made,  but  distinctions  not  so  easily.  In  consider 
ing  them  as  distinct  formations  I  am  borne  out  by 
the  result  of  the  observations  of  Humboldt  and 
Macculloch — and  no  other  authority  need  be  cited. 
The  short  portion  of  time  allotted  for  this  course 
allows  of  no  discussions,  nor  would  they  be  profit- 
able. I  shall  therefore  proceed  to  an  account  of  the 
other  members  of  the  primary  family.  Some  of 
them  are  indeed  very  small,  but  not  less  important 
in  a  geological  point  of  view, 

SERPENTINE,  is  a  beautiful  rock  presenting  some 
shade  of  green  mixed  with  white,  yellow,  brown  or 


168 

red ;  and  its  name  has  been  derived  from  the  fanci- 
ful arrangement  of  the  colors,  bearing  some  resem- 
blance to  the  skin  of  a  serpent. 

Its  surface  is  glossy,  though  dull,  and  offers  to 
the  finger  that  saponaceous  feeling,  so  peculiar  to 
all  magnesian  rocks  and  minerals,  indicating  the 
presence  of  Magnesia. 

It  seems  to  hold  the  first  place  among  these  less 
extensive  members  of  the  primary  class  in  any  ar- 
rangement founded  on  the  age  of  rocks,  as  it  is  not 
unfrequently  found  resting  immediately  on  granite. 

It  does  not  appear  to  be  stratified,  nor  is  there 
any  reason  for  supposing  it  to  be  so.  It  differs 
from  all  unstratified  rocks  in  having  no  veins  run- 
ning into  the  neighbouring  strata.  In  Aberdeenshire 
it  is  included  in  granite;  but  in  Great  Britain  it 
occurs  mostly  among  gneiss,  argillite,  hornblende 
rocks  and  limestone,  and  occasionally  in  mica  slate. 
It  rests,  forming  the  chief  component  of  white- 
stone,  on  ancient  granite,  in  the  Erzeberg.  It  is 
occasionally  covered  by  gneiss  and  sometimes  by 
mica  slate.  A  small  formation  of  it  in  Saxony  rests 
on  gneiss,  and  is  riot  covered  by  any  other  rock. 
In  S?.  America,  on  the  mountains  of  Higuerote,  it 
occurs  in  a  similar  position.  The  large  formations 
of  this  rock  are  posterior  to  argillite. 

With  whatever  rock  Serpentine  may  be  connect- 
ed, it  forms  intimate  associations.  When  in  con- 


169 

tact  with  limestone,  the  two  rocks  frequently 
blend.  A  gradation  may  be  sometimes  traced  from 
serpentine  to  hornblende,  to  which  it  is  intimate- 
ly connected.  It  has  been  observed  that  when 
veins  of  trap  pass  through  secondary  limestone,  it 
is  converted  into  serpentine  during  its  passage,  and 
by  an  interchange  of  the  imbedded  minerals  be- 
longing to  either,  a  gradation  may  be  established 
between  trap  and  limestone. 

It  is  sometimes  connected  with  carbonate  of  lime, 
and  thus  forms  the  beautiful  marble  called  verde 
antique. 

The  texture  varies  from  highly  crystalline  to  com- 
pact and  earthy.  It  is  susceptible  of  a  polish,  and 
is  highly  prized.  The  precious  serpentine  is  in 
small  quantities,  and  is  very  beautiful. 

Serpentine  is  the  repository  of  many  imbedded 
minerals,  some  of  which  occur  in  such  quantities 
as  materially  to  alter  its  character.  The  list  fol- 
lows : 


Asbestos 
Amianthus 
Steatite 
Diallage 
Hornblende 
Actynolite 
Qjuartz 

tremolite 
Talc 
Jade 
Pyrope 
Calc.  Spar 
Idocrase 
Garnets 

Chrysolite 
Opal 
Chromate  of  iron 
Oxydulous  iron 
Lithomarge 

It  is  seldom  the  gangue  of  metals— In  Cornwall 
it  is  blended  with  native  copper,  and  in  Piedmont 
it  is  associated  with  beds  of  magnetic  iron. 


170 

It  is  not  an  uncommon  rock  in  Europe.  It  forms 
the  top  of  Monte  Rosa,  and  of  Pindus — and  of  the 
Appenines  generally. 

In  this  country  it  forms  an  insulated  mass  at  Ho- 
boken.  At  Rye,  W.  Chester,  it  occurs,  and  will  re- 
ceive a  good  polish.  Near  New  Haven  it  is  found 
with  large  beds  of  lime  stone,  and  is  quarried  ex- 
tensively. At  Westfield  (Mass.)  it  is  enclosed 
in  granite,  in  very  small  quantites. 

PRIMARY  LIMESTONE  is  a  very  interesting  rock, 
of  which  our  information  is  not  very  accurate.  It 
is  only  by  a  close  examination  of  the  geological 
position  that  it  can  be  known — as  it  bears  a  strong 
resemblance  to  the  secondary  marbles — and  more 
particularly  to  that  portion  usually  called  Transi- 
tion, and  thus  offers  another  argument  to  Dr.  Mac- 
culloch  for  his  wishing  to  embrace  this  latter  class 
in  the  Primary  Rocks — It  is  a  remarkable  rock, 
composed  almost  entirely  of  calcareous  matter. 

The  colours  are  so  various  as  scarcely  to  be 
subject  of  definition  They  are  usually  derived 
from  inflammable  matter,  from  a  mixture  of  other 
substances — or  from  iron.  The  most  esteemed  is 
the  white,  which  bears  a  fine  polish,  and  is  some- 
times translucent. 


171 


It  has  been  used  for  centuries  for  ornamental 
purposes  in  sculpture  and  architecture.  Many  of 
the  noblest  monuments  of  Grecian  artists  are  in 
marble. 

The  white  marble  of  the  Alps  and  of  the  Vallais 
is  highly  prized.  The  grand  cathedral  of  Milan  is 
built  of  primary  marble  from  the  Lago  Maggiore, 
as  well  as  the  suberb  triumphal  arch  of  Napoleon, 
which  his  spiritless  successor  has  left  unfinished — 
a  monument  of  his  illiberally  and  want  of  taste. 

I  shall  briefly  notice  a  few  of  the  more  valuable 
and  rare  antique  and  modern  marbles ;  though  this 
belongs  more  particularly  to  mineralogy. 

The  Parian  marble  of  the  ancients  was  snow 
white,  with  the  slightest  possible  tinge  of  yellow, 
the  grain  fine,  and  when  polished  the  appearance 
was  somewhat  waxy.  By  exposure  to  air  it  har- 
dened, and  thus  resisted  decomposition  for  centu- 
ries. It  receives  the  most  delicate  touches  of  the 
chisel,  and  retains  them  for  ages,  with  all  the  soft- 
ness of  wax  and  the  mild  lustre  of  the  original  polish. 
The  finest  Grecian  sculpture  that  has  descended  to 
us,  is  in  this  marble.  The  Venus  di  Medici-  the 
Venus  of  the  capitol — the  Diana  Venatrix — the 
Colossal  Minerva,  the  recumbent  Ariadne — Juno 
Capitolina,  and  Diana  and  the  Stag,  in  the  Louvre, 
are  all  formed  of  this  marble. 


172 

The  Pentelic  marble,  from  mount  Penteiicus, 
near  Athens,  closeh  resembles  the  preceding — but 
is  more  compact  and  of  a  finer  grain.  When  the 
Arts,  at  a  very  early  period,  had  attained  their  full 
splendor  in  the  age  of  Pericles,  the  Grecians  pre- 
fered  this  marble  to  the  Parian,  probably  because 
it  was  nearer.  The  Parthenon  was  built  entirely 
of  it — as  were  many  Athenian  works,  erected  du- 
ring the  administration  of  Pericles,  as  the  superb 
temple  of  Ceres,  or  Eleusis. 

Among  other  beautiful  relics  are  the  torso  of  the 
Belvidere — and  the  muses  of  the  Vatican — and  in 
Paris,  a  Bacchus  in  repose — the  throne  of  Saturn 
— and  the  tripod  of  Apollo.  It  was  remarked  by 
Dr  Clark  that  while  the  works  executed  in  Parian 
marble  remain  perfect,  those  finished  in  the  pentelic 
marble  have  been  decomposed. 

The  marmo  greco  was  obtained  from  Scio 
and  Samos,  in  the  Archipelago. 

The  white  marble  of  Luni  on  the  coast  of  Tusca- 
ny takes  so  fine  a  polish  and  so  delicate  a  touch 
that  the  Grecian  artists  latterly  prefered  it  to  all 
others.  The  Antinous  of  the  Capitol  is  of  this  mar- 
ble, and  the  Apollo  Belvidere, "  the  statue  that  en- 
tranced the  world." 


173 

T  he  white  marble  of  Carrara  is  of  this  formation. 
The  quarry  was  first  opened  by  Julius  Cresar  and 
it  has  ever  since  been  highly  prized. 

Foreign  marbles  were  introduced  to  a  great  ex- 
tent among  the  Romans.  Pliny,  who  wrote  1 66 
years  after  the  first  importation  of  marbles,  remarks 
the  rapid  progress  that  had  taken  place  in  that 
period,  from  a  simple  and  unadorned  way  of  life  to 
magnificence  and  extravagant  expense.  In  the 
reign  of  Diocletian,  240  years  afterwards,  the  im- 
portation of  foreign  marbles  was  discontinued,  as 
the  columns  employed  in  the  baths  of  Diocletian 
were  taken  from  more  ancient  buildings.  The 
large  and  superb  obelisk  in  the  Circus  Maximus  of 
Rome,  was  brought  to  the  city  after  this  period 
however.  Its  removal  from  Egypt  was  began  by 
Constantine,  and  finished  by  his  son.  For  remove- 
ing  this,  it  may  be  remarked,  the  largest  wrought 
stone  ever  moved  in  Europe,there  existed  sufficient 
mechanical  skill  at  that  period,  although  the  arte 
connected  with  design  had  considerably  declined. 

The  white  marble  of  mount  Hymmetus  in  Greece 
— the  translucent  white  marble  or  Marmo  Statua- 
rio  of  the  Italians — the  flexible  white  marble. — 
the  roso  antico — the  verde  antico — the  giallo  anti- 
co — the  antique  cipolin  and  the  antique  african 
24 


174 

breccia  are  among  the  ancient  marbles  of  this  for- 
mation. 

The  red  and  white  Tiree  marbles,  the  lona  marble 
and  the  marble  of  Skye,  and  many  others  of  Scot- 
land— The   Mona  marble   of  Anglesea — and  the 
black  marble   of  England;  the  Waterford,  and  the 
Tipperary  and  the   Kerry  marbles  of  Ireland — 
the  Languedoc  and  Campan  of  France — the   Si- 
enna— the  mandelato — the  green  marble  of  Flo- 
rence— the  Verdi  di  Prado — the  Rovigo — the  Luni 
-the  Venetian — the  Laggo  Maggiora,  the  Bretonico 
— and  the  Bergamo  marbles  of  Italy — the  thousand 
and  one  marbles  of  Sicily — and   generally  speak- 
ing, the  marbles  of  Spain,  of  Portugal,  Switzerland, 
Germany,  Norway,  Sweden  and  Russia  are  of  this 
formation  :  as  was  the  red  marble  of  mount  Sinai. 
But  we  need  not  look  abroad  for  primary  mar- 
bles.    We  have  a  locality  of  it  at  Kingsbridge  ; 
where  it  is  coarse  grained,  and  contains  mica. 

At  Singsing  is  a  much  better  and  finer  variety, 
and  one  that  deserves  to  be  employed  more  exten- 
sively. 

The  Schuylkill  marble  is  extensively  and  deserv- 
edly used  in  the  arts — 

The  Potomac  breccia  marble  is  susceptible  of  a 
high  polish,  and  is  employed  extensively — the  va- 


175 

riety  of  color,  and  shape  of  the  imbedded  minerals 
give  it  a  beautiful  appearance.  The  shafts  of  the 
columns  in  the  hall  of  Representatives  in  the  Capi- 
tol at  Washington  are  of  this  breccia  :  they  are 
nearly  21  feet  from  base  to  capitol,  and  2  feet  in 
diameter.  A  block  of  70  feet  long,  with  a  base  of 
1 1  feet  by  7 1  has  been  procured. 

The  quarries  of  New  Milford  about  3  miles  from 
New  Haven,  afford  fine  and  beautiful  marble — sim- 
ilar to  the  verde  antique. 

The  Swanton  marble  (Vermont)  is  a  superb  and 
excellent  variety,  and  will  eventually  be  much 
used. 

The  Smithfield  marble  of  R.  Island  is  valuable. 

The  marble  quarries  of  Massachusetts  are  the 
most  valuable  in  this  country. 

The  West  Stockbridge  marble  is  much  used — 
and  produces  to  the  owners  about  $30,000  annu- 
ally. In  Lanesborough  about  $10,000  worth  is 
yearly  sold.  The  marbles  of  Berkshire  sell  for 
about  $40,000— and  those  of  Sheffield  for  $8,000 
yearly. 

Primary  limestone  is  found  in  strata,  of  all  forms 
and  magnitudes — also  in  nodules  or  large  irregu- 
lar masses,  in  gneiss,  and  in  veins,  when  it  is  crys- 
talized.  In  the  Pyrennees,  it  is  considered  by 
Charpentier  as  an  independent  formation.  In  South 


176 

America  it  is  found,  coarse  grained  and  white,  simi- 
lar to  the  finest  Carrara,  which  Humboldt  for  a 
Jong  time  thought  an  independent  formation.  In 
the  Pyrennees  and  in  the  Alps  it  is  common,  but  in 
America,  beds  of  it,  subordinate  to  rocks  of 
granite-  gneiss,  are  more  rare. 

In  Scotland  it  occurs  in  granite;  when  it  is  as- 
sociated with  mica  slate  or  gneiss,  the  mica  enters 
into  its  composition  and  gives  it  a  laminar  struc- 
ture. The  beds  usually  follow  the  direction  of 
the  accompanying  rocks. 

The  following  minerals,  with  others,  are  found 
in  limestone : 


Serpentine, 
Steatite, 
Garnet, 
Emerald, 
Beryl, 
Spinelle, 
Titanite, 
Sphene, 

Stilbite, 
Olivin, 
Idocrase, 
Tabular  Spar, 
Tremolite, 
Sahlite, 
Augite, 
Hornblende, 

Actinolite, 
Asbestos, 
Mica, 
Talc, 
Chlorite, 
Quartz, 
Brown  Spar, 
Pyrites. 

QUARTZ  ROCK  has  been  established  as  holding 
a  place  among  the  primary  rocks.  Dr.  Maccul- 
loch,  Humboldt,  and  Von  Buch  first  gave  us  cor- 
rect ideas  of  it. 

It  is  generally  white,  with  a  smooth,  brilliant 
surface,  or  is  tinged  with  reddish,  yellowish,  or 
dark  purple  tints. 


177 

Its  aspect  is  usually  granular — the  size  of  the 
grain  varying:  rarely  is  compact  or  crystalline. 
In  its  purest  state  it  has  different  aspects :  thus,  in 
some  cases,  it  has  a  granular,  crystali.ed  appear- 
ance :  in  others,  the  texture  is  a  mixture  of  the 
mechanical  and  chemical :  and  again,  it  is  purely 
mechanical.  The  cavities  may  contain  regular 
crystals. 

When  much  blended  with  felspar,  it  takes  the 
reddish  tint  of  that  mineral,  and  the  texture  be- 
comes changed,  so  as  to  exhibit  a  mere  agglutina- 
tion of  grains  of  different  sizes,  and  in  different 
proportions.  It  has  a  foliated  disposition,  and  the 
laminae  are  easily  separated  into  very  thin  plates. 

This  rock  is  sometimes  found  to  contain  mica, 
particularly  when  resting  on  mica  slate,  and  is 
split  into  laminae  of  such  thicknes,  as  to  allow  of  its 
being  used  for  architectural  purposes. 

A  simple  quartz  rock  1800  feet  thick  exists  at 
an  elevation  of  1600  feet  above  the  sea  in  South 
America. 

Like  the  primary  rocks,  with  which  it  is  in  con- 
nection, it  is  stratified ;  the  distinctions  of  beds  be- 
ing as  decidedly  marked  in  some  cases  as  in  sand- 
stones. The  dimensions  vary  from  an  inch  to  ma- 
ny yards ;  and  having  natural  joints,  they  break 
into  rhomboidal  or  prismatic  fragments. 


178 

It  has  no  certain  position,  being  occasionally 
found  alternating  with  all  the  primary  strata. — 
When  alternating  with  gneiss  the  limits  are  scarce- 
ly discernable,  as  the  felspar  becomes  gradually 
more  abundant,  and  the  other  components  less. 
When  alternating  with  mica  slate,  its  beds  are  very 
thin,  and  the  mica  insinuates  itself  into  the  mass — 
thus  producing  a  very  gradual  change,  so  as  to 
render  doubtful  the  line  of  demarcation.  This  is 
not  always  the  case,  for  when  they  alternate  in 
large  beds,  the  outlines  are  much  more  decided. 

Quartz  rock  alternates  with  argillite  also,  in  la- 
minae of  various  dimensions ;  generally  on  a  small 
scale.  In  some  cases,  they  almost  insensibly  glide 
into  each  other;  in  others  their  separation  is  very 
distinct.  It  alternates  also  with  greywack  schist ; 
and  sometimes,  says  Dr.  Macculloch,  with  primary 
sandstone,  which  it  strongly  resembles,  but  always 
on  a  larger  scale. 

M.  Von  Buch  remarks  that  in  Scandinavia  the 
primitive  clay  slate  is  sometimes  represented  by 
quartz  rock,  thus  making  them  geognostic  equi- 
valents. 

In  South  America,  the  quartz  rock  has  been 
examined  by  that  indefatigable  observer,  Hum- 
bold  t.  He  found  this  formation  containing  alter- 
nating beds.  1 — auriierous  quartz.  2 — chlorite 


179 

slate.  3 — auriferous  quartz  and  tourmaline.  4 — 
auriferous  quartz  and  specular  iron  ;  and  some  of 
these  beds  are  1000  feet  thick.  It  is  to  the  destruc- 
tion of  these  beds  that  some  suppose  we  are  origi- 
nally indebted  for  piatina,  gold  and  diamonds,  and 
also  for  the  topaz  and  euclase  of  Brazil. 

Some  English  geologists  have  denied  the  right  of 
quartz  rock  to  a  separate  place  ;  and  chiefly  be- 
cause there  is  so  small  a  quantity  of  it  in  Europe : 
But  in  America  it  decidedly  takes  rank — a  locality 
of  it  is  seen  running  from  Canada,  through  Ver- 
mont, Massachusetts  and  part  of  New-York,  an 
extent  of  more  than  300  miles. 

At  Brighton,  near  Boston,  it  occurs  of  various 
colours. 

It  contains  few  imbedded  minerals :  garnet, 
hornblende,  titanite  and  oxydulous  iron  occasion- 
ally occur. 

CHLORITE  SCHIST  has  only  lately  been  deemed  of 
such  importance  as  to  be  called  a  rock. 

It  is  of  a  greenish  color,  passing  into  grey,  and 
into  the  pale  grey  of  the  micaceous  schist.      The 
|  greenish  specimens  have  the  most  lustre. 

It  does  not  form  very  extensive  tracts   of  coun- 
try, but  is  sufficiently  well  marked  in  its  charac- 


180 

actersto  induce  the  best  geologists  of  the  present 
day  to  assign  it  a  distinct  name. 

It  is  so  nearly  allied  to  micaceous  schist,  with 
which  it  is  intimately  associated,  that  some  geolo- 
gists have  doubted  the  propriety  of  a  separation. 
It  alternates  also  with  gneiss,  and  by  insensible 
degrees  enters  into  that  rock.  With  mica  schist, 
argillite,  gneiss  and  primary  limestone  it  forms  a 
very  interesting  geological  series  in  Scotland. 

V*  hen  the  beds  are  thick,  it  is  strongly  assimi- 
lated to  mica  schist,  is  flexed  and  is  imperfectly  di- 
visible. It  is  more  generally  the  case  that  the 
strata  are  thin,  when  it  is  more  easily  split  into 
laminae,  but  is  seldom  applicable  to  economical 
purposes. 

In  texture,  it  partakes  of  the  characters  of  the 
rocks  with  which  happens  to  be  most  intimately 
united  at  the  locality — as  micaceous  schist,  gneiss, 
argillaceous  schist.  It  never  contains  fragments 
of  other  rocks. 

The  essential  constituents  are  quartz  and  folia- 
ted chlorite,  which  is  to  be  distinguished  from 
scaly  chlorite.  The  green  tint  of  the  former  is 
the  most  convenient  character  by  which  to  dis- 
tinguish it  from  mica,  and  from  micaceous  schist. 


181 

Other  minerals  occasionally  enter  into  its  com- 
position, as  felspar,  hornblende,  mica,  actynolite 
and  compact  felspar. 

The  imbedded  minerals  are  usually  crystallized 
chlorite,  quartz,  oxydulousiron,  tourmaline,  brown 
spar  and  pyrites. 

East  of  Troy  chlorite  schist  occurs  in  strata  be- 
tween two  and  three  miles  wide,  and  sometimes 
rising  into  hills  200  or  300  feet  high. 

On  the  Milford  Hills,  in  Connecticut,  it  is  found 
in  strata  between  primary  limestone  and  horn- 
blende ;  and  at  West  Haven,  it  forms  extensive 
strata,  passing  perhaps  into  argillite. 

TALCOSE    SCHIST    is   another     rock     that  has* 
only  been  lately  spoken  of  separately  in  geology 
and  it  is  to  the  observation  of  Macculloch  that  this, 
as  well  as  the  last  rock,  owes  its  elevation. 

It  is  similar  to  the  preceding  rock,  being  com- 
posed of  talc,  or  talc  and  quartz,  with  an  occasion- 
al, though  rare,  intermixture.    Its  colors  are  white 
lead  grey  and  dark   obscure  green.     The  pecu- 
liarities of  talc  sufficiently  distinguish  it  from  other 

rocks. 
It  is  not  common,  nor  abundant — but  alternates 

very    distinctly,  as  a  rock,  with   other  primary 

strata.    The  constituents  of  chlorite  or  micaceous 
25 


182 

schist  give  those  rocks  a  very  different  character 
from  the  present. 

The  strata  are  usually  thin ;  and  it  might  have 
been  retained  as  a  simple  mineral  did  it  not  occa- 
sionally show  itself  in  large  masses. 

Associated  with  hornblende  schist,  it  often  forms 
thin  beds  in  a  series  of  gneiss.  It  is  often  formed 
by  an  imperceptible  passage  from  micaceous 
schist :  sometimes  too  from  chlorite  schist  ;  and 
occasionally  from  argillaceous  schist.  In  all  these 
cases,  the  two  first  particularly,  it  is  associated  with 
minerals  having  an  affinity  to  talc,  as  steatite  and 
asbestos.  It  is  also  associated  with  serpentine. — 
It  presents  no  structure  particularly  to  be  noticed  : 
it  is  sometimes  minutely  undulated,  but  not  flexed 
like  micaceous  schist. 

It  contains  the  following  minerals. 


Asbestos, 

Actynolite 

Cyanite, 


Diallage, 

Automalite, 

Staurotide, 


Chromate  of  iron. 
Pyrites. 


Perhaps  the  regular  strata  of  talc,  described  by 
Professor  Hall,  as  occurring  in  Windham,  Ver- 
mont, is  Talcose  Schist. 

HORNBLENDE  Rocks  have  given  rise  to  much  dis- 
cussion in  Geology,  and  are  variously  viewed  by 
different  Geologists. 


183 

Brochant  arranges  under  this  head  greenstone, 
greenstone  porphyry ,,  and  verd  antique. 

Bakewell  considers  Trap  as  a  generic  term, 
embracing  greenstone,  basalt,  amygdaloid  and 
whinstone. 

Eaton  includes  primitive  trap,  sienite,  green- 
stone porphyry  and  green  porphyry  under  the 
Hornblende  Rocks. 

Macculloch,  under  Hornblende  Schist,  speaks  of 
hornblende  rock,  primitive  greenstone,  and  green- 
stone slate. 

When  hornblende  becomes  slaty  in  its  structure, 
it  is  usually  termed  Hornblende  Slate. 

When  intermixed  with  felspar,  it  is  then  Green- 
stone. The  proportions  of  the  two  ingredients  are 
different;  but  the  hornblende  usually  predomi- 
nates and  gives  the  greenish  tinge.  If  this  variety 
become  slaty  it  is  called  Greenstone  Slate 

Hornblende  rocks  are  not  always  composed  of 
but  two  constituent  parts  :  sometimes  admitting  in- 
to the  compound  quartz,  mica,  talc,  lime  and  iron, 
which  latter  decomposes  by  the  action  of  air,  and 
disintegrates  the  mass.  Epidote  is  occasionally 
present  in  these  rocks,  which  are  then  susceptible 
of  a  fine  polish.  When  the  felspar  is  in  crystals  it 
is  called  porphyrytic  greenstone  ;  and  this  variety, 
when  very  dark  and  fine,  was  called  by  the  an- 


184 

cients  Black  Porphyry.  The  green  porphyry  of 
the  ancients  is  very  compact,  and  embraces  crys- 
tals of  felspar.  It  is  often  colored  by  epidote. — 
This  is  found  near  Boston. 

Greenstone  beds  are  occasionally  very  large, 
forming  mountains, usually  conical,  with  mural  pre- 
cipices. It  is  not  confined  to  the  primary  class. 

In  this  country  it  is  common.  It  forms  the  sum- 
mits of  all  mountains  between  the  primary  range 
and  the  Hudson.  The  Palisades  are  of  this  rock; 
as  is  Mount  Holyoke,  in  Massachusetts,  where  the 
columns  are  from  60  to  100  feet  long,  articulated 
like  basalt.  In  Maine,  on  the  Kennebec,  it  also 
occurs. 

Dr.  Macculloch  terms  them  all  Hornblende 
Schist,  on  the  supposition,  that  the  other  rocks, 
usually  called  hornblende,  are  but  subordinate 
parts  of  the  great  beds,  having  the  schistose  struc- 
ture— and  that  the  structure  varies  from  massive 
to  schistose  in  the  same  bed.  Hum  bold  t  thinks  the 
independence  of  greenstone  slate  doubtful. 

Hornblende  Schist  rarely  forms  extensive  tracts, 
without  alternating  with  other  primary  strata. 

Its  most  intimate  association  is  with  gneiss,  in 
moderate  and  thin  strata,  so  as  almost  to  form  a 
subordinate  bed,  but  in  other  cases  to  equal  it  in 
quantity  and  importance.  It  follows  the  flexures 


185 

of  gneiss  and  is  penetrated  by  the  same  veins  of 
granite — passing  however  into  gneiss  by  the  ac- 
quisition of  quartz,  and  alternations  of  horn  blende. 
In  the  same  way  it  also  alternates  with,  and  in- 
sensibly runs  into  micaceous  schist ;  in  which  it  is 
usually  accompanied  by  chlorite  schist,  presenting 
sometimes  a  prismatic  structure.  It  is  not  often 
associated  with  argillaceous  schist,  but  is  occasion- 
ally, when  it  also  passes  gradually  into  that  rock. 
It  passes  into  Actynolite  schist,  which  is  erected 
into  a  separate  rock. 

It  often  presents  minute  undulations,  like  mica- 
eous  and  chlorite  schists,  besides  following  the 
large  flexures  of  the  laminar  varieties. 

The  texture  varies  according  to  the  component 
parts — but  the  granular,  crystalline,  and  laminar 
are  the  most  common  :  in  the  latter  case  being 
fissile  ;  in  the  former,  massive — (being  the  horn- 
blende rock  of  many.) 

It  has  not  been  found  to  contain  fragments  of 
other  rocks,  and  its  texture  may  be  set  down 
as  truly  crystalline  or  chemical. 

Its  components  are  felspar  arid  hornblende,often 
the  latter  alone:  thus  differing  from  micaceous 
and  chlorite  schists,  which  always  contain  two 
minerals,  one  of  them  essentially  quartz.  Mica 


186 

and  Chlorite  only  are  very  rarely  contained  in 
such  quantities  as  to  alter  the  genuine  rock. 

The  color  is  black  or  a  green  so  dark  as  not  to 
be  distinguished  from  it.  The  colour  of  the  fel- 
spar produces  varieties  of  shade,  as  it  approximates 
white,  green,  or  red. 

Pyrites  and  garnet  are  the  only  minerals  found 
in  this  rock — the  latter  sometimes  very  abundant. 

It  is  used  for  building  stone,  and  in  the  prepara- 
tion of  water  proof  mortar. 

ACTINOLITE  SCHIST  is  mentioned  by  Macculloch 
as  a  distinct  rock;  thus  following,  as  he  remarks, 
the  ideas  of  Saussure,  who  asserts  that  it  occurs 
in  gneiss,  under  a  distinct  character. — It  is  dis- 
tinct from  chlorite  schist.  In  all  its  associations  it 
is  similar  to  hornblende  schist,  with  the  exception 
of  a  more  intimate  connection  with  chlorite  schist. 
It  differs  from  hornblende  schist  in  composition 
only  by  the  substitution  of  actynolite  for  horn- 
blende. It  is  to  be  remarked,  that  while  actynolite 
continues  to  be  considered  as  a  distinct  species 
from  hornblende,  so  long  must  the  two  rocks  be 
separated. 

At  Brunswick,  Maine,  it  forms  a  stratified  rock 
of  considerable  extent,  associated  with  granular 
quartz. 


187 


PORPHYRY  has  been  placed  among  the  primary 
rocks,  though  Humboldt  doubts  its  existence  as 
such,  unless  in  subordinate  beds — in  the  same 
way  that  gneiss  and  mica  slate  of  the  high  Alps, 
become  granular,  and,  from  the  insulation  of  fel- 
spar crystals,  assume  a  porphyritic  aspect.  He 
considers  porphyries  as  more  closely  connected 
with  coal-sand-stone. 

Porphyry  has  a  compact  base,  containing  crys- 
tals distinctly  visible,  chiefly  of  felspar  or  quartz, 
the  base  forming  the  specific  term,  as  compact  fel- 
spar, or  clay  stone,  pitch  stone,  or  clink  stone. 

Its  color  is  reddish,  brown,  purplish,  or  green. 
Its  general  appearance  is  not  unlike  granite. 

Felspar  porphyry  is  found  near  Boston,  and 
equals  in  beauty  the  antique  varieties.  The  base 
is  compact  felspar,  and  has  been  mistaken  for  jas- 
per.— It  is  occasionally  slightly  granular,  or  a 
little  foliated.  The  fracture  is  usually  conchoidal, 
somewhat  splintery  or  uneven.  It  gives  fire  with 
steel.  When  the  crystals  of  felspar  decompose, 
small  cavities  are  produced:  even  the  base  is 
liable  to  decomposition,  but  is  protected  from  the 
action  of  air  and  moisture  by  being  polished.  It 
is  often  susceptible  of  the  finest  polish,  and  has 
been  much  employed  in  the  arts.  It  is  very  du- 


188 

rable,  and  was  highly  prized  for  architectural  pur- 
poses by  the  ancients.  The  extreme  hardness 
alone  of  porphyry  and  granite  has  caused  their 
neglect.  It  should  not  form  an  objection.  Inde- 
pendent nations  who  build  not  in  fear  of  revolu- 
tions should  have  durable  materials. 

'Some  of  the  most  beautiful  ornaments  of  Rome 
are  of  this  substance ;  the  urn  of  Constanza,  and 
theurnof  St.  Helena  are  each  formed  from  a  large 
block  of  porphyry:  and  the  great  tazza,or  saucer 
shaped  reservoir  in  the  rotunda  of  the  Museo  Pio 
Clementino  is  one  immense  piece  of  porphyry. 
Pliny  says  that  the  sculptors  began  to  use  porphy- 
ry under  Claudius.  The  room  in  which  the  prin- 
ces of  the  Greek  empire  were  born  was  encrusted 
with  it :  and  these  princes  were  called  Porphyro- 
geneti.  The  name  of  this  stone  was  taken  from 
the  ancient  purple  dye  made  of  the  Tyrian  shell 
fish  called  porphyrios,  whence  it  is  supposed  that 
the  ancient  dye  was  of  this  dull  red  colour. 

There  is  a  small  grained  greenish  porphyry, 
more  highly  prized  than  the  red  variety. 

SIENITE  is  another,  and  the  last  of  these  rocks. 
By  the  substitution  of  one  ingredient  for  another, 
granite  is  so  insensibly  converted  into  sienite,  thaf 


189 

at  first  sight  it  does  not  strike  us.  Thi  is  effected 
by  the  existence  of  hornblende  in  the  granite, 
which  becoming  more  abundant,  at  last  supplies 
the  place  of  quartz,  and  forms  a  compound  of 
which  hornblende  and  felspar  are  the  two  constant 
and  essential  constituents :  but  in  which  mica  and 
epidote  may  occasionally  blend.  Felspar  is  usual- 
ly the  most  abundant,  and  occasionally  the  horn- 
blende is  in  very  small  quantities.  The  necessary 
presence  of  hornblende  as  an  ingredient,  distin- 
guishes this  rock  from  granite  in  which  hornblende 
is  imbedded. 

It  derives  its  name  from  Siena  in  Upper  Egypt, 
where  it  abounds,  and  whence  it  was  brought  in 
great  quantities  for  employment  in  architecture 
and  sculpture,  by  the  Greeks  and  Romans. 

Its  structure  is  granular  and  sometimes  slaty. 

The  color  varies  with  the  predominating  consti- 
tuent ;  the  hornblende  often  gives  it  a  greenish 
tinge,  as  does  epidote  :  fie  felspar  is  mostly  red- 
dish, or  whitish.  When  there  are  large  crystals 
of  felspar  contained  in  a  fine  grained  sienite,  the 
mass  is  termed  Sienitic  Porphyry.  It  will  have 
been  observed,  that  sienite  and  greenstone  are 
both  composed  of  felspar  and  hornblende.  They 
are  in  fact  the  same  rock  varied  by  a  transition  so 

gentle   as    to    be    imperceptible :   thus,   granite 
26 


190 
/ 
changes  into  sienite,  which  runs  into  greenstone  : 

"but  that  section  of  the  chain  in  which  hornblende 
predominates  is  greenstone,  and  where  felspar  is 
the  most  abundant,  it  is  sienite. 

This  rock  is  occasionally  associated  with  all  the 
primary  rocks,  resting  on  granite,  gneiss,  and  ar- 
gillite — and  alternating  with  all  the  lesser  members 
of  this  family. 

It  is  not  an  abundant  rock. 
It  is  plentiful  on  the  west  shore  of  Lake  Cham- 
plain. 

In  many  places  in  Massachusetts  it  is  so  abun- 
dant as  to  be  quarried.  The  Stone  Chappie 
in  Boston,  the  State  Prison  at  Charlestown,  and 
the  prison  at  Lechmere  Point  are  of  this  stone. 
The  two  celebrated  lions  at  the  steps  ascending 
the  Roman  C  apitol  are  of  sienite  ;  as  is  also  the 
famous  Collosal  Egyptian  Head  in  the  British 
museum. 

Humboldt  doubts  if  it  ever  occurs  as  a  primary 
rock,  except  as  a  subordinate  bed,  or  as  an  indepen- 
dent primary  formation.  Such  he  thinks  are  some 
sienites  resting  on  gneiss,  and  partly  covered  by 
primitive  mica  slate.  He  mentions  the  Sienite  of 
Paramo,  placed  on  granite  and  covered  bv  slate. 


191 

These  are  the  substances  usually  treated  of  in 
Geology,  under  the  head  of  Primary  Rocks  :  to 
them  Humboldt  has  added  "  EUPHOTIDE,"  a  variety 
of  serpentine  rock  ;  or  a  mixture  of  diallage  and 
lamellar  felspar.  It  is  the  Gabbro  of  de  Buch.  It 
seems  to  be  most  intimately  connected  with  mica 
slate  and  hornblende  schist. 

All  these  rocks  are  not  necessarily  present  in 
every  primary  country  :  i.  e.  they  do  not  univer- 
sally hold  the  same  position,  since  part  of  them 
may  be  absent.  Indeed  we  have  been  taught  dur- 
ing the  last  twenty  years,  as  M  Humboldt  says, 
that  we  are  not  to  expect  precisely  the  same  rela- 
tive position  in  the  constituents  of  the  great  forma- 
tions. The  great  laws,  however,  regulating  the 
succession  of  rocks,  in  the  structure  of  the  globe, 
are  in  all  countries  the  same  ;  and  striking  analo- 
gies in  the  position,  composition,  and  included  or- 
ganic remains  of  contemporary  beds  exist  univer- 
sally :  and  viewing  formations  in  a  general  way  we 
are  almost  taught  to  believe  their  universal  identi- 
ty. But  identity  of  formations  is  not  to  be  looked 
for,  any  more  than  the  constant  operation  of  the 
same  law  in  mechanics.  Like  causes  produce  like 
effects — but  obstacles  may  present  occasionally 
to  interrupt  them — thus  occasionally  one  rock 
may  represent  another :  in  which  case  there  is  not 


192 

an  identity  in  all  formations,  but  parallel  forma, 
dons,  or  geognostic  equivalents.  Nor  in  comparing 
widely  distant  countries,  are  we  to  look  in  one 
country  for  an  equivalent  for  every  rock  in  the 
other,  as  one  formation  may  represent  many  others. 
Thus  the  beds  of  clay  below  the  chalk,  in  France, 
may  be  easily  separated  from  oolitic  limestone  ; 
but  in  our  hemisphere,  South  of  the  Equator,  they 
have  marl  for  geognostic  equivalents  to  represent 
them.  And  these  beds,  by  the  way,  may  in  the 
same  manner,  represent  the  chalk  in  the  United 
States. 

The  striking  similarity  of  structure  in  different 
countries  has  been  examined  and  acknowledged  by 
the  best  geologists :  thus  the  position  and  succes- 
sion of  formations  has  long  been  a  subject  of  study 
to  Humboidt;  (whom  I  liberally  resort  to)  and  in 
South  America  he  soon  recognised  the  conformity 
of  superposition  in  the  two  continents,  and  found 
them  fully  develloped  in  the  formations  exhibited 
from  the  21°  N.  Lat.  to  the  12°  S.  Lat.-  where  he 
says  the  types  were  rather  enlarged  than  altered. 
From  the  Canary  Islands  to  within  the  polar  cir- 
cle (as  far  as  the  71°  N.  Lat.)  we  have  undoubted 
testimony  oi  the  uniformity  of  position,  and  of  the 
analogous  features  that  characterise  formations  in 
the  most  distant  regions. 


193 

The  associations  of  rocks,  upon  comparing  im- 
mense fields  of  observation,  we  may  say,  are  near- 
ly as  constant  as  their  composition.  The  com- 
pounds are  made  up  of  the  same  simple  minerals, 
and  in  turn  compose  mountain  masses,  in  which 
the  same  rocks  are  found  in  a  similar  position. 

This  uniformity  of  position  is  observed  usually 
in  rocks  of  all  formations — but  more  particularly 
in  the  larger,  or  older,  as  in  the  Primary  and  Secon- 
dary :  it  does  not  follow  that  it  is  found  in  inde- 
pendent formations.  These  independent  forma- 
tions are  so  called  from  the  fact,  that  they  rather 
escape  the  law  of  uniformity  of  position,  being 
placed  indiscriminately  on  granite,  micaceous 
schist,  and  secondary  limestone.  The  position  of 
independent  formations  however  does  not  neces- 
sarily exclude  uniformity  of  position. 

It  has  been  doubted  by  some  whether  the  same 
rock  was  deposited  at  the  same  time  in  different 
parts  of  the  globe. — Most  Geologists  assign  the 
same  date  to  a  deposit  wherever  it  may  be  found : 
this  is  expressed  by  the  term  Isochronism  of  forma- 
tions. Formations  of  analogous  composition  are  al- 
lowed to  have  been  produced  at  different  and  dis- 
tant periods — these  however  are  formations  not  in- 
cluded in  this  general  law— as  Primary  and  Se- 


194 

eondary  Limestone.  Organic  remains  go  far  to 
prove  this  Isochronism,  and  the  existence  of  the 
same  fossi's  in  similar  though  distant  beds  affords 
strong  proofs. 

"  It  has  more  than  once  been  desired  that  we 
could  find  a  supplement  to  our  short  annals  in 
the  monuments  of  nature.  The  historical  ages 
might,  however,  have  sufficed  to  teach  us,  that  the 
succession  of  moral  and  physical  events  is  not  re- 
gulated by  the  uniform  process  of  time,  and  cannot. 
in  consequence,  furnish  its  measure.  We  see,  in 
looking  back,  a  succession  of  creations  and  dis- 
tinctions, by  the  various  arrangements  of  beds 
that  form  the  crust  of  our  globe.  They  give  us  an 
idea  of  several  distinct  epochas :  but  these 
epochas,  so  fertile  in  events,  may  have  been  very 
short,  compared  to  the  number  and  importance  of 
the  results.  Between  the  creations  and  destruc- 
tions on  the  contrary,  we  see  nothing,  whatever 
might  be  the  immensity  of  the  intervals  ;  there 
every  thing  is  lost  in  the  mist  of  indeterminable 
antiquity,  the  degrees  of  which  cannot  be  appre- 
ciated, because  the  successsion  of  phenomena  has 
no  scale  that  can  be  referred  to  the  division  of 
time."  (Mem.  de  1'Institute,  18J5.) 


195 

I  have  mentioned  that  several  of  the  rocks  we 
have  described,  alternate  with  others,  with  which 
they  are  associated.  When  the  same  rocks  are 
placed  several  times  alternately  upon  each  other, 
they  are  said  to  alternate,  and  it  is  often  by  this  in- 
terchange of  places,  that  they  insensibly  become 
blended  and  run  into  each  other.  Thus  when  two 
formations  succeed  each  other  immediately,  it 
generally  happens  that  beds  of  the  one  begin  at  first 
to  alternate  with  beds  of  the  other,  until  a  new 
formation  succeeds  without  any  subordinate  beds. 

In  primary  rocks  the  three   most  ancient   are 
said  to  be  either  insulated,  or  alternating  two  and 
two,  or  all  three  alternating  together.    Granite  and 
gneiss  in  some  cases  are  constantly  associated,  in 
others  gneiss  and  mica  slate.     In  all  cases   there 
are  certain  laws  ; — granite,   gneiss  and  mica  slate 
are  found   in  a  triple  association  ;  but  granite  al- 
ternating with  mica  slate  only,  or  gneiss  and  mica 
slate  alternating  with  argillite  only,  are  said  not  to 
occur.    Those  rocks  passing  insensibly  into  others 
with  which  they  are  in  contact  must  not  be  con- 
founded in  this  way — as   micaceous  schists   that 
oscillate     between  gneiss    and    argillite,    are   not 
to  be  confounded  with  such  rocks   as   alternate, 
and  preserve  distinct  all  their  characters. 


196 

In  treating  of  mountains,  I  have  mentioned  their 
usual  direction  as  being  frequently  the  same. 

The  parallelism  of  beds,  called  also  Loxodrom- 
ism,  is  very  surprising.  The  primary  beds  on  the 
coast  of  Genoa,  the  plains  of  Lombardy — the  Alps 
of  St.  Gothard — Swabia  and  the  north  of  Ger- 
many, were  first  noticed  by  Humboldt  to  run  almost 
constantly  from  south  west  to  north  east — and  this 
was  one  of  the  reasons  that  led  him  to  South  Ame- 
rica, where  he  noticed  the  same  in  the  chain  of 
mountains  running  from  the  lower  Oronoko  to  the 
basin  of  the  Rio  JSigro,  and  the  Amazon.  This 
Loxodromism  has  already  been  mentioned  in 
speaking  of  the  uniform  direction  of  mountains 
from  north  east  to  south  west. 

This  is  the  direction  of  our  Allegany  Mountains, 
one  of  our  most  interesting  geological  features. 
From  the  sources  of  the  St.  John  River,  New 
Brunswick,  it  runs  south  west  to  the  junction  of  the 
Alabama  and  Tombigbee  Rivers.  At  the  distance 
of  from  40  to  8u  miles  it  follows  and  skirts  the  At- 
lantic, forming  a  mighty  barrier  to  a  mighty 
ocean. 

Granite,  gneiss,  and  micaceous  schist,  each  form 
a  considerable  part  of  this  immense  ridge.  Gra- 
nite is  found  on  the  tops  of  mountains  and  on 


197 

plains,  and  is  frequently  so  decomposed  as  to  have 
lost  adhesion  for  50  or  100  feet  below  the  surface, 
exhibiting  only  sand  and  gravel. 

Gneiss  is  more  widely  distributed — and  covers 
nearly  half  of  the  primary  ridge,  including  immense 
beds  of  granite,  some  of  them  300  feet  thick ;  ip 
which  beds  are  found  the  Emerald,  Tourmaline, 
Garnet,  &c. 

Micaceous  Schist  and  Argillite  are  also  widely 
distributed. 

Primary  Mountains  may  be  said  generally  to 
be  unfavorable  to  vegitation  :  their  extreme  hard- 
ness, their  precipices,  and  unfriendly  soil,  doom 
them  to  barrenness.  Lichens  and  mosses  attached 
to  their  sides  decay,  and  furnish  soil  for  larger 
plants — Water  penetrates  and  breaks  off  masses — 
the  influence  of  air,  water,  heat  and  light  assist  in 
the  progress  of  disintegration — and  insensibly,  but 
uniformly  and  constantly,  aid  in  converting  stones 
into  bread — or,  in  other  words,  in  preparing  soil 
from  the  most  sterile  rocks  for  the  support  of  ani- 
mal and  vegitable  life. 

The  decomposition  of  granite  is  slow,  and  when 
decomposed  the  unfriendly  siliceous  grains  are 
easily  washed  away.  There  is  neither  vegitable  nor 
animal  matter  in  the  compound ;  it  does  not  absorb 


27 


198 

moisture,  letting  the  water  percolate  ; — nor  does 
it  retain  heat. 

The  soil  made  from  gneiss  is  not  washed  away 
quite  so  easily — and  the  mica  yields  it  more  ar- 
gillaceous earth — but  it  is  seldom  deep  (from  20 
to  100  feet.) 

Micaceous  Schist  and  Argillite  decompose  more 
rapidly,  and  form  a  better  though  not  a  good  soil. 

The  rivers  of  primary  districts  have  rocky 
beds  and  precipitous  banks. 

Upon  the  whole,  Primary  Mountains  are  covered 
with  a  soil  less  productive  than  the  other  classes  of 
rocks — and  form  the  barren  regions  of  the  Arctic, 
and  the  sterile  plains  of  the  Torrid. 

'to  compensate,  in  some  degree,  their  water  is 
more  pure  and  clear,  and  the  inhabitants  more 
healthy. 


, 


f 


LECTURE  VI. 

Transition  Rocks — Jlrgillite — Greywacke — Lime* 
stone — Gypsum — Porphyry — Sienite — Greenstone. — 
Secondary  Rocks — Observations  on  their  Formation — 
Old  Red  Sandstone — Coal — Indications  of  it,  &c. — 
Shale — Limestone — Rock  Salt — Variegated  Sandstone 
— Shell  Limestone  — Lias — Oolites — Iron  Sand—Green 

Sand — Chalk.       Tertiary    Formations of  France, 

England,  and  the  United  States.      Alluvia — Diluvia — 
Overlying  Rocks — Conclusion 

Resting  on  the  Primary  Rocks  already  descri- 
bed, we  find  others,  that  have  been  denominated 
by  Werner,  Transition,  by  others,  the  Interme- 
diate, the  Medial,  the  Sub  Medial,  and  by  Hutton, 
the  Stratified.  They  never  attain  the  elevation  of 
the  preceding  rocks,  and  are  more  liable  to  de- 
composition. They  are  considered  as  not  crys- 
talline. They  are  the  oldest  or  lowest  rocks  in 
which  we  find  any  record  of  vegitable  or  animal 
existence,  and  may  be  regarded  as  ancient  re- 


200 

cords,  imprinted  with  the  natural  history  of  the 
inhabitants  of  the  globe. 

They  repose  on  the  primary  class,  and  form  a 
contrast  to  their  bold  precipices  and  rugged  peaks, 
by  their  less  pointed,  and  more  beautiful  outline. 

In  retaining  the  term  Transition,  I  do  violence 
to  my  own  opinions.  The  division  of  rocks  in 
which  that  term  is  adopted  is  unnecessary  and  per- 
plexing. I  have  elsewhere  given  reasons  for  not 
employing  it — the  following  may  be  mentioned. 

The  Rocks  called  Transition,  are  often  as  pure- 
ly chemical  in  composition  as  any  other  rock. 

Many  of  them  contain  no  organic  remains. 

There  is  no  definite  boundary  between  them  as 
a  class  and  the  primary.  And  lastly  it  is  a  division 
of  no  practical  importance  ;  and  one  that  is  very 
perplexing  to  the  student. 

In  America,  they  have  no  line  of  demarcation, 
and  are  often  absent  altogether. 

If  we  place  these  rocks  among  the  primary,  as 
some  Geologists  do,  we  shall  then  have  natural 
limits  to  every  class — the  red  sandstone  being 
placed  between  the  primary  arid  secondary — and 
the  chalk  between  the  secondary  and  tertiary. 

I  shall  however  retain  this  name,  as  I  do  not 
consider  my  own  authority  sufficient  to  banish  it, 


201 

although  in  so  doing,  I  should  but  follow  the  most 
natural  division,  and  be  upheld  by  some  of  the 
best  geological  enquirers. 

The    rocks    usually    described    as     transition 
are  but   varieties   of  those  we  have  al- 
ready mentioned — viz. 


Argillite, 

Greywacke, 

Limestone,  (metalliferous) 

Gypsum, 


Porphyry, 

Sienite, 

Greenstone. 


ARGILLITE. — It  is  but  a  few  years  since  this  rock 
has  been  assigned  to  different  formations  ;  having 
until  lately  been  termed  Transition.  But  when  en- 
quirers into  nature  began  to  examine  for  themselves 
and  were  no  longer  led  by  the  great  masters  of  the 
opposite  schools,  the  structure  of  the  Earth  was 
more  thoroughly  examined,  and  new  facts  discover- 
ed, which  tended  to  clear  up  many  of  the  supposed 
inconsistencies  in  geological  speculations  :  thus  the 
oscillations  and  alternations  of  beds  and  strata 
cleared  up  the  supposed  irreconcileable  positions 
in  which  masses  were  occasionally  found,  and 
which  no  theory  accounted  for. 

The  composition  of  transition  Argillite  is  the 
same  as  that  of  the  primary,  viz.  Siliceous  and 


202 

Argillaceous  Earths,  Magnesia,  Lime,  and  Oxide 
of  Iron. 

It  has  various  shades  of  grey,  varying  to  pur- 
ple, red  and  green. 

It  is  soft  and  easily  decomposed ;  and  is  fusible. 
It  rests  upon  gneiss  or  mica  slate.  It  contains 
beds  of  limestone,  and  alternates  with  the  rocks 
in  its  vicinity,  frequently  having  grejwacke 
interposed. 

It  splits  into  laminae,  and  is  then  useful  for  va- 
rious purposes  :  that  which  is  easily  divisible  into 
thin  plates,  and  is  compact  and  sonorous,  is  term- 
ed roof  slate. 

Some  varieties  of  it  are  used  for  writing  slates. 
It  frequently  abounds  in  iron  pyrites,  which  ren- 
ders it  unfit  for  use.  It  also  contains  alum  slate, 
and  flinty  slate. 

It  is  an  abundant  rock.  That  termed  transition  is 
more  plentiful  than  that  before  noticed.  The  ele- 
vations composed  of  it  are  usually  tabular  and 
flat. 

I  have  already  mentioned  that  Argillite  is  quar- 
ried in  Rensselaer  County. 

In  the  vicinity  of  Hudson,  it  is  seen  forming  the 
banks  of  the  river,  and  is  found  on  and  near  the 
banks  of  the  Hudson  as  far  north  as  Fort  Miller, 


203 

•:^"     - 

It  frequently  contains  metallic  treasures.  In 
Guanaxuato.  in  New  Spain,  this  rock  is  traversed 
by  a  vein  that  for  17  years  produced  annually 
556,000  marks  of  silver.  A  mine  in  this  rock  in 
Valencia  yielded  JbO,000  marks  of  silver  annually 
for  40  years. 

Argillite  sometimes  contains  porphyry  arid  sien- 
ite.  In  the  North  of  Europe  the  three  alternate. 

When  Argillite  contains  imbedded  grains  and 
masses  of  indurated  clay,  quartz  and  flinty  slate,  it 
then  forms  what  is  termed 

TRANSITION  GREYWACKE,  denominated  fine  or 
coarse  according  to  the  size  of  the  grains :  when 
the  former  variety  is  slaty,  it  is  then  called  Grey- 
wacke  Slate,  which  is  in  fact  coarse  argillite,,  and  by 
a  combination  with  mica,  passes  into  mica  slate. 

It  alternates  with  flinty  slate  and  limestone.  In 
England  two  formations  of  Greywacke  alternate 
with  two  formations  of  limestone. 

It  is  closely  allied  to  the  preceding  rock,  argil- 
lite  passing  into  greywacke  slate,  which  has  a 
homogeneous  appearance  and  a  slaty  structure. — 
It  is  distinguished  from  it  only  by  its  grey  color, 
and  by  the  glimmering  of  the  mica  it  contains. 

In  a  general  sense,  Greywacke  means,  accord- 
ing to  Humboldt,  every  conglomerate,  sandstone, 
or  puddingstone,  fragmentary  or  arenaceous  rock 


204 

of  transition  formation,  that  is  anterior  to  the  red 
sand  stone  of  the  coal  formation,  (old  red  sand- 
stone.) In  a  more  limited  sense,  it  is  confined  to 
the  arenacious  transition  rocks,  which  contain  only 
small  fragments  of  simple  substances,  more  or  less 
rounded  ;  for  instance,  of  quartz,  of  lydian  stone, 
of  felspar,  and  of  clay  slate,  but  not  fragments  of 
compound  rocks.  In  the  latter  case,  the  term 
greywacke  is  inadmissable,  and  the  name  of  brec- 
cias or  conglomerates,  with  large  primitive  fragments, 
is  given  to  various  agglutinations  of  pieces  of  gra- 
nite, gneiss,  and  sienite. 

Calcareous  puddingstones  are  those  in  which 
rounded  fragments  of  carbonate  of  lime  are  cemen- 
ted by  a  base  of  the  same. 

Coarse  greywacke  passes  easily  into  conglomer- 
ates with  large  fragments,  and  alternates  with 
those  of  fine  grain  and  homogenious  aspect.  The 
puddingstones  and  breccias  with  large  fragments 
of  primitive  and  compound  rocks  are  true  grey- 
wackes. 

Greywacke  is  metalliferous.  It  is  oi'ten  traver- 
sed by  quartz.  The  novaculite,  or  hone  slate,  be- 
longs to  it,  as  does  the  rubblestone  or  rubble- 
wacke  which  is  connected  with  the  Catskill  Moun- 
tains. 


205 

Kedwacke  is  seen  in  a  layer  between  the  vil- 
lage of  Catskill  and  the  mountain,  which  has  now 
become  so  fashionable  a  resort. 

Mr.  Eaton  says  that  this  rock  underlays  all  the 
western  part  of  our  state.  In  Rensselaer,  Wash- 
ington, and  Columbia  Counties,  it  is  often  met  with 
covering  extensive  tracts. 

Alternating  with  these  two  last  mentioned  rocks 
occurs  a  Limestone,  called  TRANSITION  LIMESTONE, 
Metalliferous  Limestone,  and  Carboniferous  Limestone. 
Part  of  this  formation  is  the  Mountain  Limestone  of 
some  Geologists,  who  treat  it  separately.  It  is 
compact  and  has  not  the  crystalline  structure  of 
the  limestone  formerly  spoken  of  Werner  called 
the  lower  beds  of  this  rock  transition  limestone, 
and  the  upper  he  termed  floetz— but  this  distinc- 
tion is  justly  abolished ;  and  the  two  are  properly 
spoken  of  together.  Humboldt  has  divided  it  in- 
to granular  talcose  limestone,  and  black  limestone, 
but  places  both  under  the  same  head.  Their 
characters  coincide — and  it  is  only  their  relative 
position  that  induced  Humboldt  to  give  them  these 
names  in  his  excellent  work  on  the  superposition 
of  rocks.  They  are  both  metalliferous,  and  con- 
tain traps  and  amygdaloids.  They  occur  in  vast 
masses,  and  form  mountains  with  perpendicular 

cliffs  and  steep  ravines. 
28 


206 

The  lowest  beds  usually  rest  on  argiilite, 
with  which  they  alternate.  They  contain  some 
carbon,  (about  0.75  or  |  pr.  ct.)  whence  they  derive 
their  colors,  which  vary,  usually  having  a  greyish 
hue,  and  always  darker  than  the  primary.  The  stra- 
ta are  not  well  marked,  and  are  of  great  thickness. 
Organic  remains  are  rare  in  this  rock — the  cata- 
logue is,  however,  very  curious  and  instructive. — 
The  black  limestone  contains  orthoceratites  several 
feet  long — entrochites,  madrepores,  pectinites  and 
ammonites.  It  is  extremely  difficult  to  draw  the 
line  of  boundary  between  the  upper  and  lower 
beds. 

Some  of  the  celebrated  marbles  of  antiquity  be- 
long to  this  deposit — as  the  marmor  luculleum — 
the  nero  antico — the  African  flowered  marble — 
the  pavonizzo,  and,  according  to  Humboldt — the 
gilded  breccia. 

I  have  already  mentioned  that  a  difference  oi 
opinion  exists  in  regard  to  the  manner  in  which 
we  find  the  series  of  these  rocks  contorted.  It  is 
from  the  limestone  series  that  many  of  the  argu- 
ments are  drawn. 

The  strata  of  limestone  countries  present  many 
interesting  phenomena — and  which,  if  we  allow 
the  action  of  either  of  the  discordant  agents,  i? 
easily  accounted  for.  The  arguments  of  Huttoru 


207 

Playfair  and  Hall  are  specious,  and  to  him  who 
hears  only  the  arguments  of  one  school,  carry 
conviction.  That  the  undulations  of  strata  have 
received  their  several  characters  in  a  horizontal 
position,  can  readily  be  imagined  and  easily  ac- 
quiesced in.  But  not  so  with  the  irregularities, 
contortions  and  disruptions.  Here  the  other 
school  interposes,  and  is  strongly  aided  by  argu- 
ments drawn  from  nature.  It  must  be  admitted, 
that  when  Hutton  allowed  a  certain  agency  to  wa- 
ter, and  a  certain  power  to  the  action  of  subter- 
ranean heat,  he  combined  the  good  of  both  theo- 
ries, and  appears  above  the  rank  of  a  mere 
theorist.  , 

The  upper  portions  of  this  deposit  contain 
peculiar  fossils— many  of  which  appertain  to  spe- 
cies now  extinct. 

It  is  a  singlar  circumstance  that  a  part  of  our 
globe  should  be  covered  by  animal  secretion,  yet 
such  is  the  fact,  as  was  shown  when  speaking  of 
coral  reefs. 

In  this  and  the  succeeding  rocks,  organic  re- 
mains, or  petrifactions,  become  so  frequent,  as  by 
many  to  be  supposed  characteristic  of  the  differ- 
ent beds  in  which  they  are  found — Of  the  accura- 
cy of  these  remains  as  a  geological  standard,  I  hare 
spoken  elsewhere  ;  but  I  cannot  omit  here  to 


208 

mention  the  sentiments  of  Humboldt,  who,  in  treat- 
ing of  these  rocks,  observes,  "Although  we  are  yet 
far  from  being  able  to  complete  the  history  of  ma- 
ny intermediate  and  secondary  formations  by  an 
enumeration  of  the  fossils  found  in  them,  we  shall 
indicate  some  that  characterise  this  group — (in 
which  he  includes  transition  argillite,  with  grey- 
wacke,  greenstone,  black  limestone,  sienite  and 
porphyry.) 

In  argillite  and  greywacke,  monocotytedon 
plants,  perhaps  anterior  to  the  most  ancient  ani- 
mals, entrochites,  coralites,  ammonites,  hys- 
teriolites,  orthoceratites,  pectinites,  trilo  bites, 
in  which  no  traces  of  eyes  are  disernable  ;  ogygies 
of  Brongniart,  in  which  the  eyes  are  indicated  on- 
ly by  two  tuberosities  on  the  scutum — (found  in 
our  country) — calymene  of  Tristan,  and  calymene 
macrophtalme  of  Brongniart. 

In  the  most  ancient  beds  of  the  limestone,  entro- 
chites, madrepores,  belemnites,  sometimes  insula- 
ted ammonites,  orthoceratites,  asaphus  buchii. 
asaphus  hausmanii,  and  a  very  few  bivalve  shells. 
In  the  newer  beds  of  limestone,  calymene  blumen- 
bachii,  (found  on  the  Miami)  asaphus  caudatus  of 
Brongniart,  ammonites,  terebratulites,  orthocera- 
tites, some  gryphites,and  encrinites." 


209 


This  formation  is  to  be  studied  in  many  places 
in  the  western  part  of  our  state.  At  Trenton  Falls 
on  West  Canada  Creek,  a  place  now  often  visited, 
it  contains  many  of  the  beautiful  fossils  pecu- 
liar to  it.  Orthoceratites,  nautilites,  terebratulae, 
productae,  encrinites,  and  trUobites — among  which 
is  the  beautiful  new  genus  of  Isotelus,  lately  insti- 
tuted by  Dr.  Dekay.* 

Gypsum,  porphyry,  sienite  and  greenstone  are 
found  among  these  rocks  :  Gypsum,  however,  does 
not  occur  in  sufficient  quantity  to  be  noticed.  In- 
deed it  is  doubted  if  in  a  geological  system,  it 
should  be  mentioned  at  all,  except  as  an  occasion- 
al rock,  as  other  than  secondary,  it  is  so  sel- 
dom found  in  this  place.  According  to  Brochant 
it  is  found  in  connection  with  transition  limestone. 

Porphyry,  sienite,  greenstone  and  amygdaloid 
have  already  been  noticed  :  they  occur  here  in 
small  quantities  as  occasional  rocks,  or  rather  as 
alternating  with  others,  and  have  some  characters 
distinct  from  their  earlier  beds — being  less  crys- 
talline and  more  compact. 

PORPHYRY,  having  a  base  of  indurated  clay,  is 
usually  mentioned  as  transition  porphyry.  Its 
fracture  is  dull  and  earthy.  It  is  moderately  hard 

*See  Annals  of  Lyceum  of  Nat.  Hist,  of  N.  Y.  vol.  1. 


210 

and  adheres  to  the  tongue.     The  colors  are  grey, 
greenish,  brown,  &c.  with  a  tinge  of  red  or  yellow. 

It  sometimes  presents  a  columnar  aspect.  Oc- 
casionally it  contains  nodules  with  a  centre  of  cal- 
cedony.  It  is  liable  to  decomposition,  and  resem- 
bles volcanic  products.  When  in  the  vicinity  of 
coal,  it  contains  vegitable  remains. 

Porphyry  alternates  mostly  with  argillite,  sien- 
ite,  greenstone  and  black  limestone. 

In  South  America  all  the  porphyry  is  found  in 
the  most  western  and  elevated  part  of  the  conti- 
nent, none  being  found  east  of  the  Andes,  through- 
out the  whole  eastern  part  of  South  America. 

The  Cordilleras  contain  perhaps  the  greatest 
mass  of  porphyry  :  it  is  particularly  rich  in  gold 
and  silver  ;  and  associated  intimately  with  rocks 
produced  or  changed  by  fire.  The  limits  between 
the  transition  porphyry  and  volcanic  rocks  of 
South  America  are  not  easily  traced. 

The  porphyry  of  Mexico  is  rich  in  silver  and 
gold.  The  pit  of  del  Encino  furnished  50,000 
marks  of  silver  annually  for  a  long  time.  In 
]  726-7,  two  workings  in  South  America  yielded 
542,000  marks,  almost  twice  as  much  as  all  Eu- 
rope and  Asiatic  Russia  in  the  same  time. 

Most  of  the  porphyries  of  South  America  ex- 
hibit a  tendency  to  a  regular  stratafication,  which 
is  seldom  observed  in  Europe. 


211 

SIENITE  and  GREENSTONE  have  already  been 
mentioned,  as  transition  rocks  ;  they  occur  in  in- 
timate association  with  each  other,  with  porphyry 
and  with  amygdaloid ;  the  hornblende  of  porphyry 
often  becoming  more  distinct  in  the  sienite,  and 
finally  abounding  in  the  compact  and  sonorous 
greenstone.  When  the  crystals  imbedded  in  por- 
phyry are  exchanged  for  oval  or  diamond  shaped 
substances,  the  mass  is  called  AMYGDALOID.  Indu- 
rated clay,  greenstone,  or  wacke,  may  constitute 
the  bed,  and  the  almond  shaped  nodules  may  be 
calcareous  spar,  quartz,  zeolite,  hornblende,  calce- 
dony,  agate,  epidote,  felspar,  &c.  &c.  One  mine- 
ral only  is  usually  found  in  a  cell ;  but  occasion- 
ally there  are  two  or  three  surrounding  a  nucleus. 

At  Mount  Holyoke,  in  Massachusetts,  it  occurs 
precisely  similar  to  some  European  localities.  It 
is  found  near  Boston,  and  frequently  in  Maryland. 

In  the  synopsis  at  the  end  of  this  work,  these 
substances  will  be  found  mentioned. 

These  are  the  unimportant  varieties  of  the  pre- 
ceding rocks  usually  classed  as  Transition,  but 
which  in  fact  should  be  considered  as  primary, 
where  Lehman  placed  them,  and  whence  they 
should  never  have  been  removed. 


We  often  find  that  novelties  in  Science  are  re- 
prehensible. Few  are  capable  of  understanding 
and  appreciating  the  many  and  often  distant  bear- 
ings that  one  point  has  upon  many  others,  and  of 
discriminating  between  the  relations  they  bear 
each  other.  A  fancied  difference  does  not  always 
constitute  a  true  distinction.  It  is  this  accuracy 
of  discrimination  which  placed  some  of  the  oldest 
naturalists  so  far  above  many  of  our  own  day  5 
and  assigns  to  Linnaeus  a  place,  to  which  all  the 
research  and  philosophy  of  a  more  enlightened 
period  can  elevate  very  few  of  the  living  na- 
turalists. 

«  •>' "  '•* 

In  accounting  for  rocks  other  than  the  primary, 
the  theories  of  Geologists  coincide,  as  both  Wer- 
ner and  Hutton  considered  them  as  original  depo- 
positions  from  aqueous  solution — But  the  situation 
of  the  strata  as  we  now  find  them,  has  caused 
much  discussion.  That  they  were  originally  hori- 
zontal is  granted  :  the  question  is,  how  were  they 
placed  in  the  inclined  or  vertical  position  ?  The 
disciples  of  Werner,  or  the  Neptunian  school,  sup- 
pose that  in  the  original  formation  of  these  rocks, 
there  existed  immense  caverns,  such  as  we  often 
see  at  the  present  day,  and  that  these  have  fallen 
in,  and  thus  caused  the  inclination  of  beds,  &c. ;  a 


213 

supposition  rendered  in  some  measure  probable 
by  the  immense  extent  of  many  existing  caves — 
by  the  quantity  of  water  now  running  through 
them — and  by  the  great  power  which  it  is  known 
to  exert.  In  all  Limestone  countries  they  exist 
even  now — and  rain  and  moisture  oozing  through 
crevices  may  have  filled  many,  more  or  less,  the 
softer  parts  of  the  wall  may  have  been  dissolved 
or  worn  away — and  the  roof  and  super-imposed 
strata  have  fallen  in. 

It  is  urged  against  this  theory,  that  instead  of 
the  strata  having  fallen  in,  the  primary  rocks  have 
been  forced  up  into  the  superincumbent  mass. 

The  disciples  of  Hutton,or  the  volcanic  school, 
conjecture  that  after  these  strata  were  hardened, 
they  were  elevated  with  the  primary  rocks,  then 
in  a  state  of  igneous  fusion,  by  some  force  below. 
The  recent  discoveries  of  Sir  Humphry  Davy  have 
been  supposed  to  throw  light  on  the  expansive 
power  of  heat,  and  to  furnish  strong  evidence  in 
favor  of  this  theory,  which  is  said  thus  to  stand  the 
test  of  experiment,  and  to  be  more  clearly  explain- 
ed by  the  progress  of  knowledge.  On  the  other 
hand,  it  is  asked  what  is  that  influence  exerted  by 
Alpine  chains  on  beds  at  the  distance  of  of  400 
miles  ?  Is  it  a  fact  that  there  existed  at  the  same 

great  depth  a  force  which  heaved  up  mountains 
29 


214 

and  bent  the  strata  of  the  plains,  so  that  the  bent 
edge  of  those  strata,  formerly  horizontal,  are  now 
all  inclined  at  nearly  the  same  angle  ?  Were  the 
Alpine  chains  heaved  up  ?  If  so,  it  is  singular  that 
they  issued  from  fissures  all  parallel  to  the  direc- 
tion of  the  pre-existing  inclined  beds. 

The  secondary  rocks  repose  universally  on 
those  we  have  already  described.  They  are  less 
elevated,  and  their  angles  with  the  horizon  less 
than  the  preceding.  They  have  an  unconforma- 
ble  position  to  the  primary,  usual!) ,  though  not 
necessarily.  It  may,  however^  be  laid  down  as  a 
rule,  that  all  rocks  succeeding  to  any  one  rock 
that  is  unconformable  in  position  to  the  prima- 
ry, belong  to  the  secondary.  Red  sandstone  is 
the  lowest  that  has  universally  this  position,  and 
may  therefore  be  justly  mentioned  as  the  oldest 
secondary  rock,  and  all  above  it  belong  to  the 
same  class.  They  rest  on  the  sides  of  primary 
ridges  or  at  their  feet,  and  compose  the  interven- 
ing vallies.  Their  texture  is  more  or  less  earthy, 
very  rarely  crystalline.  They  are  often  mechanical 
mixtures  composed  of  parts  of  the  primary  rocks, 
united  by  cement.  Their  horizontal  position  and 
the  presence  of  large  numbers  of  animal  and  vegit- 
able  remains  are  also  characteristics.  They  are 


215 

usually  unstratafied.  None  of  these  characters 
are  so  invariably  marked  as  the  geological  posi- 
tion ; — the  associations  of  a  rock  being  among  its 
most  valuable  and  steady  characters. 

The  number  of  secondary  rocks  is  much  more 
limited  than  the  primary,  being  confined  mostly 
to  sandstone,  limestone  and  shale — but  present  a 
great  variety  in  detail,  even  independent  of  their 
organic  contents. 

The  extent  and  depth  of  secondary  rocks  are 
also  more  limited  than  the  primary.  If  they  were 
not  often  absent,  the  primary  would  never  be  seen 
on  the  surface.  The  primary,  in  fact,  constitute 
the  great  mass  of  the  globe — while  the  secondary 
are  partial,  as  a  covering  to  them.  The  primary 
may  be  considered  universal,  since  they  bear  the 
same  characters  in  every  part  of  the  world  ;  and 
could  we  have  access  to  them,  they  would  most 
probably  be  found  in  a  similar  and  uniform  posi- 
tion every  where.  The  secondary  can  only  be 
considered  universal,  inasmuch  as  similar  rocks 
occur,  as  far  as  their  chiet  characteristics  are  con- 
cerned, in  every  part  of  the  globe.  But  they  are 
not  continuous,  and  therefore  only  partial — even 
perhaps  partial  in  a  more  limited  sense,  as  some 
varieties  are  peculiar  to  certain  countries,  and  not 
found  at  all  in  others.  Their  laws  are  not  so  gen- 


216 

eral,  operating  only  on  a  limited  or  local  scale, 
while  the  laws  of  the  primary  seem  to  have  ex- 
tended over  the  whole  globe. 

The  occasional  absence  of  these  secondary  is 
owing  to  two  causes.  The  action  of  the  elements, 
which  in  the  lapse  of  ages,  mu*t  have  destroyed 
them  partially ;  and  the  original  deposition  seems 
to  have  been  often  local,  and  confined  to  concavi- 
ties, technically  termed  basins. 

The  chief  members  of  the  Secondary  Class  may 
*be  reduced  to  four,  viz. 

1.  Red  Sandstone,  or  Great  Coal  Deposit. 

2.  Alpine  Limestone— or  Magnesian  Limestone : 
with  Rock  Salt. 

3.  Arenacious  and  Calcareous  Deposits ;  which 
embrace  the   variegated    sandstone,  or  new   red 
sandstone,  gypsum  and  rock  salt,  shell   limestone, 
sandstone,  lias,  marie,  oolite,  ferruginous  sand  and 
green  sand. 

4.  Chalk. 


RED  SANDSTONE  is  one  of  the  most  important 
rocks  of  this  class.  It  is  also  called  old  red  sand- 
stone to  distinguish  it  from  a  newer  variety  called 
also  red  marie  or  variegated  sandstone. 


217 

it  is  formed  of  the  fragments  of  the  preceding 
rocks  or  minerals — varying  from  coarse  to  fine, 
according  to  the  size  of  the  grains. 

It  rests  always  on  the  preceding  rocks  ;  varying 
in  appearance  as  it  is  more  or  less  mixed  with  ad- 
ventitious minerals.  The  simple  minerals  enter- 
ing into  its  composition  are  quartz,  frlspar,  clay, 
mica,  arid  carbonate  of  lime.  The  rocks,  which 
by  their  fragments,  contribute  to  the  formation  of 
this  one,  are  all  of  the  primary  class. 

It  contains  few  imbedded  minerals,  which  re- 
mark is  applicable  to  all  the  secondary  rocks — 
Sulphat  of  strontian  and  calcareous  spar  are  the 
most  common. 

It  contains  very  few  organic  remains. 

Its  color  is  red  as  the  name  denotes — varying 
from  a  bright  ochre  to  the  darkest  brown,  or  even 
blackish  purple. 

This  rock  is  so  immediately  connected  with 
coal,  as  to  be  treated  of  with  it  in  all  works  on 
geology. 

Where  beds  of  old  red  sandstone  are  associated 
with  calcareous  beds,  good  soil  is  generally  pro- 
duced. 

The  summits  of  mountains  composed  of  this 
rock  are  mostly  covered  with  mosses. 


COAL  is  so  intimately  associated  with  this  rock, 
that  I  cannot  persuade  myself  to  pass  it  unnoticed. 
Indeed  its  value  and  importance  to  our  city  ranks 
it  among  the  most  useful  of  all  formations,  and  one 
of  the  most  interesting  of  all  mineral  strata.  I 
may  perhaps  be  allowed  to  dwell  upon  it,  as  it  is 
a  subject  of  primary  interest  to  our  City  and 
State. 

The  oldest  variety  of  coal  that  exists  is  the 
slight  trace  of  carbon  that  we  find  occasionally  in 
primary  rocks ;  but  never  in  sufficient  quantity  to 
work. 

We  are  not  to  look  for  coal  in  any  of  the  rocks 
that  we  described  at  our  last  lecture;  nor  in  those 
that  I  have  just  mentioned.  It  is  never  found  in 
rocks  older  than  the  red  sandstone,  in  connection 
with  which  it  is  most  generally  found,  occasionally 
alternating  with  other  rock  or  earthy  strata.  It 
forms  one  of  the  most  important  branches  of  geo- 
logical science. 

The  lateral  extent  of  coal  deposits,  often  called 
1  fields,  is  sometimes  very  considerable. — 
In  many  places  they  occupy  basin  shaped  cavities, 
having  all  the  edges  turned  up,  and  perhaps  crop- 
ping out :  In  other  places  they  are  inclined  at  such 
angles  that  their  extent  cannot  be  known,  or  con- 
jectured. It  is  usual  for  more  than  one  bed  to  be 


219 

ibund  in  a  deposit ;  and  sometimes  ten  or  twenty 
are  found.  At  Liege  there  are  sixty  beds  alter- 
nating with  sandstone,  limestone,  shale,  clay 
and  sand.  The  thickness  of  a  bed  varies  from  an 
inch  to  many  feet  or  yards. — The  strata  are  gene- 
rally divided  by  natural  joints,  more  or  less  perfect 
and  extensive,  by  which  they  are  formed  into 
cuboidal  or  prismatic  masses. — They  are  usually 
laminar. 

The  mineral  composition  of  coal  does  not  strict- 
ly come  within  my  province,  yet  as  it  is  not  gen- 
erally understood,  it  may  be  noticed  in  the  brief- 
est possible  manner. 

All  the  Bitumens  from  Naptha  to  Asphaltum, 
consist  of  compounds,  apparently  indefinite,  of  car- 
bon and  hydrogen  principally  :  the  small  quanti- 
ties of  oxygen  and  azote  which  they  contain,  ap- 
pearing to  have  little  or  no  effect  in  modifying  the 
mineral  characters.  In  the  most  fluid,  the  hydro- 
gen predominates,  diminishing  progressively  ac- 
cording to  the  order  of  their  relative  tenacity  or  so- 
lidity. Where  asphaltum  ends  this  series,  cannel 
coal,  with  some  interruption  in  composition,  and  a 
considerable  one  in  texture,  commences  that  of 
coals.  From  this  variety  down  to  the  most  perfect 
anthracite,  there  is  a  similarly  indefinite  range  of 
composition: the  hydrogen  generally  diminishing  as 


220 

the  coal  becomes  less  inflammable,  as  it  is  less  ca- 
pable of  being  separated  into  bitumen  and  char- 
coal by  distillation,  and  as  it  yields  a  smaller  com- 
parative proportion  cf  the  former.  Thus  the  com- 
position of  the  bitumens  illustrates  that  of  the  se- 
veral varieties  of  coal.  The  most  perfect  anthra- 
cite appears  to  yield  no  bitumen,  yet  it  contains 
hydrogen  perhaps  in  every  case;  as  that  element 
is  present  even  in  common  charcoal,  which  is  it- 
self a  compound  substance.  Where  anthracite 
passes  to  plumbago,  which  may  in  fact  be  con- 
sidered as  the  true  end  of  this  series,  the  hydro- 
gen seems  to  have  disappeared  ;  and  if  this  sub- 
stance be  not  mere  carbon,  as  it  probably  is  not, 
from  the  apparent  combustion  which  it  undergoes, 
on  exposure  to  air,  when  its  base  has  been  extri- 
cated from  iron  under  water,  it  undoubtedly  ap- 
proaches nearer  to  that  element  than  any  of  the 
preceding  substances. 

We  all  know  that  there  are  several  varieties  of 
coal,  and  that  it  is  of  the  utmost  importance  to  us 
as  housekeepers  as  well  as  proprietors  of  land  to 
know  their  distinctive  characters  and  names. 

Anthracite,  or  native  mineral  carbon,  or  blind 
coal  is  the  first  we  shall  notice.  It  is  not,  strictly 
speaking,  a  coal,  though  combustible.  Its  color  is 
black  or  brownish,  but  seldom  the  black  of  true 


221 

coal.  It  presents  the  most  beautiful  irised  or  tar- 
nished colors.  It  is  harder  than  common  coal,  but 
breaks  easily.  It  soils  the  fingers — has  an  unctuous 
feel — aud  is  somewhat  slaty.  It  burns  slowly,  and 
with  difficulty— yielding  little  or  no  flame,  nor 
smoke,  nor  bituminous  odour.  After  burning  it 
leaves  about  23  pr.  ct.  of  grey  ashes.  It  yields  no 
bitumen,  and  the  very  feehle  flame,  which  it  occa- 
sionally exhibits,  appears  to  arise  from  the  hydro- 
gen of  the  water  it  contains. 

Anthracite,  like  the  Diamond,  appears  to  be  es- 
sentially composed  of  pure  carbon,  but  in  a  very 
different  state  of  aggregation.  That  from  Kilken- 
ny yields  97  parts  in  100  of  carbon — that  from 
Rhode  Island  95. 

When  once  ignited,  Anthracite  yields  an  in- 
tense and  lasting  heat — and  much  ot  the  difficulty 
of  kindling  it  may  be  avoided  by  the  addition  of 
a  certain  quantity  of  charcoal,  and  by  the  proper 
application  of  a  strong  current  of  air. 

Being  composed  mostly  of  pure  carbon,  without 
any  bitumen  or  sulphur,  except  occasionally  from 
pyrites,  it  burns  without  caking,  and  is  very  useful 
on  all  occasions  where  strong  and  uniform  heat  is 
requisite.  In  all  manufactories,  and  for  the  forge, 
it  is  inestimable. 


30 


222 

In  speaking  of  the  primary  rocks,  in  our  last 
Lecture,  I  mentioned  that  they  contain  no  coal;  i.  e. 
— we  know  of  no  coal  mine  in  such  rocks  as  gra- 
nite, gneiss,  &c. — But  this  Anthracite,  which  I 
have  stated  is  not  a  true  coal,  is  found  in  the  pri- 
mary rocks.  And  hence  it  is  obvious  that  this 
combustible  has  not  proceeded  from  the  decom- 
position of  vegetable  substances,  since  it  is  gener- 
ally acknowledged  that  the  primary  rocks  were 
formed  previous  to  the  existence  of  vegetation. 

We  have  abundance  of  this  combustible  in  the 
United  States. 

Rhode  Island  coal  is  this  very  substance.  It  is 
there  found  near  the  surface  covered  by  shale  and 
sandstone.  It  contains  94  pr.  ct.  of  pure  carbon. 
In  Massachusetts  also  it  is  found,  and  in  some  of 
our  new  states.  In  Arkansas  it  is  of  good  quality 
and  in  abundance. 

The  most  extensive  locality,  and  of  the  greatest 
interest  to  our  city,  is  in  Pennsylvania,  on  the  north 
east  branch  of  the  Susquehannah,  and  near  the 
heads  of  the  Laxawanna,  Fishing,  Muncey,  Le- 
high  and  Schuylkill  rivers.  It  extends  down  the 
Susquehannah  to  within  10  miles  of  Sunbury,  and 
down  the  Schuyikill  to  within  20  miles  of  Reading, 
and  is  lost  under  Peters'  Mountain.  From  the 
north  east  branch  of  the  Susquehannah,  it  ex- 


tends  about  30  miles  east,  but  only  2  or  3  west. — 
At  Wilkesbarre,  it  runs  under  the  river.  It  ap- 
pears also  at  the  surface  of  the  country  in  beds  of 
from  20  to  30  feet  thick.  This  extensive  forma- 
tion is  worked  at  several  places — and  the  Lehigh, 
the  SchuyUill,  the  Wilkesbarre,  and  the  Laxa- 
wanna  (or  Laxawaxen  as  it  is  called)  are  from  dif- 
ferent parts  of  the  same  bed,  and  derive  their 
names  irom  the  places  near  to  which  it  is 
worked.  At  Wilkesbarre,  it  is  quarried  at  the 
surface  by  means  of  gunpowder  and  wedges. 

The  Lehigh  coal,  which  is  quarried  a  few  miles 
from  the  river,  has  been  deservedly  brought  into 
use — and  is  supposed  to  be  worth  double  the 
value  of  Virginia  coal. 

The  Schuylkill  is  in  all  essentials  the  same. 

The  Laxawanna  is  from  the  north  east  portion 
of  the  same  bed — and  has  rather  a  larger  propor- 
portion  of  bitumen — so  that  it  affords  rather  more 
flame,  and  cakes  more  than  the  others. 

We  will  all  have  an  opportunity  soon  of  forming 
correct  estimates  of  their  comparative  value. 

Besides  Anthracite,  there  is  another  mineral 
often  spoken  of  as  coal,  which  is  in  fact  a  different 
substance.  I  mean  Lignite,  of  which  there  arc 
several  species,  all  derived  from  wood  that  has 


been  buried  below  the  surface,  and  decomposed. 
Jet,  of  which  ornaments  are  made,  is  one  species. 
The  Bovey  coal  of  England,  is  oi  this  kind  It 
does  not  occur  in  such  quantities  as  to  be  quarried 
for  fuel. 

At  Cape  Sable  (Maryland)  it  occurs  in  beds  of 
5  or  12  feet  thick.  At  Martha's  Vineyard  it  oc- 
curs in  small  quantities. 

True  coal  is  always  black,  and  shining,  com- 
pact, and  with  an  even  fracture.  It  is  too  hard  to 
be  scratched  by  the  finger  nail. 

True  coal  burns  easily,  with  a  whitish  flame, 
yielding  a  black  smoke,  and  a  slight,  but  not  un- 
pleasant smell  of  bitumen.  It  never  leaves  less 
than  3  pr.  ct.  of  residuum,  sometimes  much  more. 

It  is  essentially  composed  of  charcoal  and  bitu- 
men, in  different  proportions,  the  carbon  chiefly 
predominating,  and  sometimes  composing  3-4  of 
the  whole. 

It  is  easily  distinguished  from  Anthracite,  which 
burns  with  difficulty,. does  not  give  a  white  flame, 
nor  the  black  smoke,  nor  the  bituminous  odor  of 
coal. 

The  different  coals  pass  into  each  other,  but 
seldom  or  very  rarely  pass  into  anthracite. 

The  cannel,  candle,  or  parrot  coal,  the  slaty 
€oal,  the  coarse  coal,  and  the  sooty  coal  are 
only  varieties. 


225 

Coal  is  usually  found  in  beds,  at  greater  or  less 
elevation.  At  New  Castle,  where  there  are  27 
beds,  it  is  upon  a  level  with  and  below  the  sea. 
At  Whiteh^ven  it  is  400  yards  below  the  sur- 
face, and  the  working  extends  1700  yards  beneath 
the  sea. 

In  our  country  coal  is  found  at  no  great  elevation : 
but  in  South  America,  at  the  table  land  of  Santa  Fe 
de  Bogota,  it  rises  1 360  toises,  or  1 3.500  feet  above 
the  level  of  the  sea,  and  at  Huanuco,  it  is  2300 
toises  above  the  sea,  and  near  the  limits  of  per- 
petual snow. 

The  Origin  of  coal  is  by  most  geologists  attri- 
buted to  the  decomposition  of  vegetable  matters 
in  the  interior  of  our  earth.  The  remains  of  ve- 
getables that  accompany  coal,  and  the  carbon  and 
hydrogen  of  its  composition,  render  this  idea  very 
probable.  It  has  been  objected .  that  we  sometimes 
find  in  beds  of  coal,  vegetables  that  are  scarcely 
decomposed. 

It  is  generally  allowed  that  coal  has  been  pro- 
duced after  the  creation  of  organised  bodies;  and 
that  previous  to  its  consolidation  it  has  been  at 
least  partially  fluid,  either  by  solution  in  water,  or 
by  the  action  of  heat  under  comprebsion :  which 
accounts  ibr  its  crystalline  structure,  and  often  for 
te  contained  minerals. 


226 

There  is  a  remarkable  uniformity  in  the  position 
of  coal  and  its  accompanying  minerals,  in  all  parts 
of  the  world.  It  is  usually  found  under  a  thin 
layer  of  shale,  which  is  called  the  roof.  The 
stratum  beneath  the  coal  is  called  its  floor. 

Whatever  cause  produced  coal,  it  has  been  ma- 
ny times  repeated — hence  the  great  number  of 
beds  of  coal  in  the  same  mine,  under  the  same 
circumstances. 

From  whatever  fluid  coal  was  deposited,  that 
fluid  was  in  a  state  of  rest  at  the  time  of  the  de- 
position, since  the  leaves  of  fern,  &c.  which  are 
found,  are  always  in  an  expanded  state.  Jameson 
notices  a  trunk  of  a  tree  40  feet  long,  rising  through 
a  coal  formation.  At  New  Castle,  one  was  obser- 
ved 30  feet  long,  of  which  the  trunk  and  large 
branches  were  petrified,  or  become  siliceous, 
while  the  small  branches,  the  bark,  and  the 
leaves,  had  been  converted  into  coal. 

In  the  coal  mine  of  Treuil.  near  St.  Etienne,  in 
France, 4k  are  found  a  great  number  of  trunks,  pla- 
ced in  a  vertical  position,  traversing  all  the  layers 
of  a  bed.  It  is  a  real  forest  of  monocotyledonous 
vegetables,  in  appearance  rest  mbling  bamboos  or 
the  large  equisetum.  petrified  on  the  spot." 

Similar  facts  have  been  observed  in  the  coal 
fields  of  Scotland,  in  the  mines  of  Maneback,  and 
in  Saxony. 


227 

We  have  large  quantities  of  coal  in  this  country. 
— Illinois,  Missouri,  Indianna,  Kentucky,  and  Ten- 
nessee have  it  in  abundance.  In  Ohio  there  are 
all  varieties  of  true  coal.  That  of  Virginia  ex- 
ists in  great  quantity.  3ut  here  we  again  turn  to 
Pennsylvania,  one  third  of  which  state  rests  on 
coal.  The  west  side  of  the  Susquehannah  river, 
from  near  the  mouth  of  the  Juniata,  through  all 
the  country  watered  by  the  west  branch  of  the 
Susquehannah  and  its  streams,  to  Pittsburg,  and 
thence  down  the  Ohio  and  its  streams,  contains 
coal  of  a  good  quality.  At  Pittsburgh  it  approach- 
es the  surface. 

It  is  to  be  observed  that  the  situation  I  have 
here  given  to  our  true  coal,  is  different  from  that 
assigned  to  the  Anthracite  of  Lehigh  and  the 
Schuylkill. 

As  this  subject  has  become  of  great  interest, 
and  as  much  time  and  money  have  been  expended 
in  fruitless  searches  for  this  valuable  article,  mere- 
ly from  the  want  of  a  few  simple  facts,  it  may  not 
be  improper  to  notice  a  few  circumstances  which 
we  should  always  have  in  mind,  when  coal  is  the 
object  of  our  researches. 

It  may  be  laid  down  as  an  invariable  rule,  that 
good  coal  in  sufficient  quantity  to  work,  is  never 


iound  in  primary  rocks — as  granite,  gneiss,  &c. 
so  that  the  idea  of  coal  being  found  in  the  High- 
lands of  the  Hudson,  is  without  foundation.  It  is 
possible  that  anthracite  may  be  found,  but  no 
coal.  * 

Neither  are  we  to  look  for  coal  on  Long  Island, 
nor  in  the  low  lands  of  New-Jersey.  The  Lignite 
or  Bovey  coal  may  exist  there,  and  be  valuable : 
but  it  is  very  doubtful  if  the  quantity  would  be  of 
consequence. 

From  the  position  in  which  I  have  stated  coal  to 
be  found,  it  is  evident  that  at  least  one  edge  of  every 
seam  of  coal  must  rise,  in  some  place,  to  the  surface: 
and  we  must  examine  all  thoseplaces  where  strata 
have  a  chance  of  being  exposed,  as  rivers,  gullies, 
small  streams,  and  ditches;  from  some  of  which 
we  will  soon  learn  the  possibility  of  finding  the 
object  of  our  search.  White  and  red  sandstone 
are  not  always  in  company  with  coal — but  shale, 
containing  small  balls  of  iron  stone,  and  small 
thin  strata,  in  the  composition  of  which,  arid  be- 
tween the  layers  of  which  there  is  the  slightest 
tinge  of  coal,  are  never  found  except  near  coal 
fields. 

*  While  correcting  this  proof,  we  have  seen  in  possession  of 
Dr.  Dekay,  specimens  of  anthracite,  said  to  be  found  in  this 
locality. 


229 

Though  the  seam  of  coal  comes  to  the  surface, 
still  it  is  liable  to  decomposition,  and  on  that  ac- 
count may  be  found  covered  by  and  mixed  with 
clay,  gravel,  or  sand,  in  which  case,  the  mass  above 
is  usually  found  to  contain  small  pieces  of  coal. 
If  these  are  found  in  a  ravine,  we  may  be  sure  the 
seam  of  coal  is  higher  up  than  the  spot  where  they 
occur.  Sometimes  too,  the  superficies  of  a  coal 
seam  becomes  in  part  dissolved,  and  presents  a 
black  friable  bed  on  the  surface ;  and  should  this 
occur  on  a  side  hill,  it  often  gradually  descends 
so  as  to  cover  a  large  space,  becoming  thinner 
as  it  descends.  This  black  bed  is  often  found  40 
or  6()  yards  from  the  real  coal — and  has  often  so 
deceived  the  inexperienced  as  to  occasion  im- 
mense sums  to  be  thrown  away  within  a  few  yards 
of  the  coal,  especially  where  the  declivity  is  rapid, 
as  then  it  is  not  so  easily  traced. 

It  is  necessary  too  to  notice  the  strata  of  rock, 
and  mark  what  angle  they  make  with  the  horizon; 
and  to  what  point  of  the  compass  they  run. — 
Sometimes  the  coal  runs  parallel  to  a  gully  or  ra- 
vine for  a  long  distance — and  other  times  crosses 
it.  In  the  last  position  it  is  more  readily  noticed. 
In  the  former,  much  trouble  and  cost  is  occasion- 
ally the  consequence. 


31 


230 

Even  when  the  appearance  of  coal  is  found,  and 
is.  favorable,  it  requires  knowledge  and  judgment 
so  to  dig  as  to  hit  the  bed.  No  accurate  idea  can 
be  formed  until  the  bed  is  so  laid  open  to  view,  as 
to  show  itself  between  the  roof  and  floor  or  pave- 
ment. We  may  then  judge  of  its  thickness,  as 
that  rarely  alters — we  may  also  judge  of  the  puri- 
ty of  the  coal,  as  it  sometimes  contains  stones  or 
pyrites — also  if  it  be  hard  or  soft,  or  if  it  will  burn 
well  or  not.  Many  beds  of  coal  improve  as  they 
descend,  and  it  is  generally  admitted,  that  all 
coal  is  better,  that  is  found  under  a  greater  mass 
of  superincumbent  strata. 

SHALE,  or  slate  clay,  or  secondary  argillite,  re- 
sembles the  argillite  already  noticed,  from  which 
it  differs  only  by  its  less  solid  and  indurated  state. 
It  is  formed  by  the  decomposition  of  older  rocks, 
and  is  fine  or  coarse,  according  to  the  size  of  the 
materials,  sometimes  even  containing  fragments  or 
large  nodules  of  rocks. 

The  texture  is  shistose,  divided  by  natural 
joints  into  beds. 

It  seldom  forms  extensive  tracts  of  country,  be- 
ing usually  subordinate  to  more  important  and 
conspicuous  formations. 


g, 

231 

'    *  ^ 

it  occurs  most  frequently  in  very  thin  strata  or 
laminae,  alternating  with  other  rocks.  It  is  as- 
sociated with  coal,  alternating  with  it,  and  often 
impregnated  with  bitumen.  It  is  found  also  with 
secondary  limestone,  forming  thin  strata,  alterna- 
ting with  calcareous  beds,  or  entering  as  a  con- 
stituent. 

Its  resemblance  to  greywacke  is  sometimes  so 
strong  as  to  deceive,  without  an  examination  of  the 
geological  position. 

It  often  contains  many  vegetable  impressions. 

The  next  rock  we  have  to  mention,  is  limestone ; 
called  MAGNESIAN  LIMESTONE,  or  Alpine  limestone. 
It  is  a  dull  rock,  of  various  colours,  usually  greyish, 
from  white  to  black,  which  it  derives  from  bitumen. 
Its  texture  is  usually  earthy — rarely  crystalline. 
This  rock  is  not  found  in  all  countries — on  the 
continent  of  Europe  it  exists  in  great  abundance, 
and  takes  the  place  of  the  rock  I  shall  next  men- 
tion. On  that  continent  it  is  the  usual  repository 
of  gypsum  and  rock  salt — two  very  important 
minerals.  The  term  Alpine  Limestone  applied  to 
this  rock,  is  unfortunate,  since  it  offers  the  idea 
that  the  Alps  are  formed  of  it:  which  is  erro- 
neous. 


232 

The  rock  salt  found  in  this  rock  is  also  always 
associated  with  a  certain  clay,  called  IVluriatife- 
rous  clay,  which  characterises  the  formation  of 
rock  salt,  in  both  hemispheres,  as  the  clay  with 
impressions  of  fern,  does  that  of  coal. 

Rock  salt  is  found  minutely  disseminated  in  this 
clay,  or  forming  large  masses —  and  this  points  out 
how  it  is  to  be  worked — whether  it  is  to  be  work- 
ed or  quarried — or  whether  the  rock  is  to  be 
washed  by  the  repeated  introduction  of  fresh  wa- 
ter, for  the  purpose  of  dissolving  the  salt,  and 
thus  bringing  it  out  in  solution.  When  the  salt 
does  not  form  true  beds,  it  is  often  found  interwo- 
ven, as  a  net  work,  running  through  the  clay  At 
other  times  it  exists  in  thin  veins.  On  the  eastern 
declivity  of  the  Andes  in  a  Peruvian  province, 
the  river  Gualaga  has  cut  its  way  through  the  skirt 
of  a  mountain  of  rock  salt,  which  also  contains  an 
ore  of  lead.  Indeed,  lead,  clay  gypsum,  and 
limestone,  are  the  usual  accompaniments  of  rock 
salt. 

In  Europe  and  in  South  America,  rock  salt  is  in- 
many  places  quarried,  and  is  open  to  day. 

Upon  comparing  the  different  localities  of  rock 
salt  in  England,  at  Bex,  (Switzerland)  on  the  Car- 
pathian Mountains,  of  Hallein.  of  Hallstadt,of  Savoy  a 
and  of  Halle  in  Tyrol,  it  has  been  noticed  that  the 


;- 


233 

deposits  of  rock  salt  in  Europe,  diminish  in  riches 
with  their  elevation  above  the  sea.  In  South 
America,  where  alone  on  our  continent,  we  have 
yet  found  rock  salt,  it  occurs  in  immense  beds, 
nearly  1 4,000  feet  above  the  ocean  :  and  only  one 
mine,  that  of  Huaura,  in  Peru,  is  richer.  It  is 
there  worked  in  the  same  way  as  a  quarry  of 
marble. 

This  limestone  has  its  peculiar  fossils,  viz.  gry- 
phites,  entrochites,  terebratulites,  pentacrinites, 
arcse,  encririites,  ammonites,  orthoceratites,  bones 
of  the  monitor,  impressions  of  lycopodiaceae,  and 
bambousaceae  and  leaves  of  dicotyledon  plants, 
analogous  to  the  willow. 

In  countries  where  this  rock  does  not  exist,  as 
in  England,  its  place  is  occupied  by  another — 
viz. 

The  VARIEGATED  SANDSTONE,  or  NEW  RED 
MARLE,  which  in  that,  and  some  other  countries,  is 
considered  as  the  peculiar  repository  of  rock  salt. 
In  most  countries,  the  salt  seems  to  have  been  de- 
posited in  basin  shaped  cavities,  similar  to  those 
in  which  we  often  find  coal.  This  is  the  case  with 
the  salt  of  Cheshire  in  England,  where  one  bed  of 
hard  salt  is  26  yards  thick.  At  C  ordova,  in  Spain, 
where  one  mass  of  salt  is  nearly  700  feet  high, 


234 

an3  more  than  1200  feet  broad,  it  is  encompassed 
by  this  rock. 

The  sandy  deserts  of  Caramania  in  Asia  afford 
rock  salt  so  hard  and  dry  that  it  is  used  as  build- 
ing stone. 

Where  rock  salt  is  not  found,  and  springs  sup- 
ply its  place,  it  is  singular  that  they  are  always 
found  in  a  line,  or  band,  as  it  were  :  and  usually 
at  or  near  the  base  of  some  mountain  chain. 

The  most  splendid  and  remarkable  deposits  of 
salt,  are  at  the  foot  of  the  Carpathian  mountains — 
the  English  mines  are  near  its  central  chain,  and  we 
may  draw  a  line  on  the  west  of  our  Alleganies,  be- 
yond which  all  our  salt  springs  are  found.  Our  own 
invaluable  springs  in  Onondago,  Cayuga,  Wayne, 
and  the  neighbouring  counties  are  sources  of 
wealth  to  our  state,  which  are  indeed  inestimable. 
In  1 800,  when  the  brine  of  Onondago  was  sup- 
posed to  be  rich,  it  afforded  but  42,754  bushels — 
In  1814,  nearly  300,000  bushels  were  manufactur- 
ed— allowing  the  state  a  revenue  of  $7,000 — and 
in  182.3,  upwards  of  6<»0,000  bushels  were  made, 
and  the  state  reaped  a  revenue  of  nearly  $76,000. 
In  1824,  the  tax  amounted  to  nearly  one 
million  of  dollars.  From  the  town  of  Salina,  above 
three  millions  of  bushels  might  be  made,  should 


235 

the  demand  require  it,  and  the  state  would  derive 
an  income  of  $375,000  from  the  brines  of  one 
village. 

The  importance  of  this  article  is  yet  to  be  dis- 
covered by  our  citizens.  The  manufacturer  and 
the  agriculturalist  are  yef  to  be  convinced  of  the 
benefits  it  can  afford  them  :  to  the  agriculturalist, 
in  particular,  it  offers  the  means  of  improving  his 
lands,  of  increasing  his  stock,  and  materially  en- 
larging his  profits. 

The  various  uses  of  salt,  its  localities,  the  plar- 
ces  where  it  may  be  found,  and  the  purposes  to 
which  it  may  be  applied,  have  been  some  months 
before  the  public  in  an  "  Essay  on  Salt,"  to  which 
I  may  refer  you. 

Reposing  on  the  Magnesian  Limestone  or  Varie- 
gated Sandstone  are  various  beds  of  lime,  under  the 
names  of  oolite,  shell  limestone,  lias,  and  marie : 
and  several  beds  of  sand,  under  the  names  of  fer- 
ruginous sand,  and  green  sand. 

« 

The  SECONDARY  LIMESTONE  occupies  an  impor- 
portant  place  in  our  country — and  covers  the  im- 
mense secondary  region  embracing  the  western 
parts  of  our  state,  extending  north  into  Canada,  to 
the  primary  ridge  of  mountains  dividing  the  waters 


236 

of  the  St.  Lawrence  from  those  of  Hudson's  Bay  ; 
and  south  to  the  Ohio. 

SHELL  LIMESTONE  (the  Muscheikalk  of  the  Ger- 
man school)  is  usually  the  lowest  of  this  class  of 
limestone,  and  is  very  similar  to  the  English  Port- 
land stone. 

It  is  characterised  by  the  great  abundance  of 
broken  shells  pervading  the  mass.  Humboldt 
supposes  that  it  has  an  oolite  for  a  geognostic  equi- 
valent. He  mentions  the  following  shells  as  be- 
longing to  it — belemnites,  chamites,  ammonites, 
nautilites,  buccinites,  trochites,  turbinites,  pecti- 
nites,  ostrocites,  terebratulites,  gryphites,  mytu- 
lites,  pectacrinites,  ericrinites,  &,c. 

What  has  been  usually  termed  the  Jura  Lime- 
stone, is  a  succession  of  beds  of  lias,  marl  and 
oolite,  of  which  the  former  is  the  lowest.  This 
unfortunate  name  was  given  to  it  by  Humboldt. — 
It  is  also  called  the  Cavern  Limestone. 

In  England  this  suite  of  formations  is  considered 
as  very  interesting,  and  occcupies  the  whole  space 
between  the  variegated  sandstone,  or  new  red 
marie,  and  the  chalk.  It  is  there  found  to  contain 
several  sub-divisions  or  beds,  each  bearing  a 
different  name. 


237 

LIAS  reposes,  in  many  places,  on  the  new  red 
inarle;  it  is  a  blueish  argillaceous  mass,  alterna- 
ting with  beds  of  limestone.  These  beds  become 
thicker  towards  the  lower  part,  white,  arid  fit  for 
lythographic  purposes.  The  fossils  of  the  lias 
are  numerous  and  beautiful.  The  following  list 
approaches  to  a  perfect  catalogue  so  far  as  we 
know,  viz. —  Ichthyosaurus,  plesiosaurus,  testudo, 
several  species  offish,  ammonites,  (about  20  spe- 
cies) those  having  the  siphuncle  in  an  elevated 
ridge,  between  two  furrows  are  characteristic  of 
this  formation. 

Nautilus,  scaphites,  belemnites,  helicina,  tro- 
chus,  tornatilla,  melania,  dentalium.  patella,  mo- 
diola,  unio,  cardita,  astarte,  area,  cucullaea,  nucu- 
la,  terebratula,  spirifer  or  pentamenus,  gryphoea, 
ostrea,  pecten,  plagiostoma,  lima,  plicatula,  hyp- 
popodium,  perna  ?  echinus,  cririoidea :  the 
following  species  of  this  genus,  pentacrinite, 
caput  medusae,  briareus,  subangularis,  basalti- 
formis,  tuberculatus :  many  remains  of  wood, 
fern,  &c.  and  a  species  of  turbinolia. 

The  most  characteristic  shells  of  this  formation 
are  the  ammonites,  (bucklandi)  the  gryphcea,  (in- 
curvata)  and  the  plagiostama,  (gigantea.) 


32 


238 

The  OOLITES  or  Roe  Stones  derive  their  name 
from  the  small  particles  embedded  in  the  mass, 
giving  it  an  appearance  similar  to  the  roe  of  fishes. 
The  principal  building  stone  of  England  is  from 
oolitic  series. 

Oolite  has  lately  been  found  in  our  country  — 
Mr.  Schoolcraft  noticed  it  regularly  stratafied,  in 
the  State  of  Illinois,  as  containing  lead  mines,  in 
connection  with  shell  limestone.  A  locality  of 
it  has  been  noticed  in  Saratoga  county  during  the 
last  summer.  As  yet  no  geologist  has  thoroughly 
examined  this  rock  in  situ  in  United  States. 

The  great  mass  of  oolites  in  England  has  been 
sub-divided,  into  three  distinct  systems,   each  of 
which  has  been  separately  studied  and  found  to  be 
rich  in   organic  remains.      They  are  separated 
by  beds  of  clay. 

The  Lower  System  or  Division  of  Oolites,  consists 
of  oolite  -mixed  with  sand,  and  fullers'  earth,  and 
embraces  the  great  oolite,  oolite  of  Stonesfield, 
cornbrash,  forest  marble,  and  Kelloway  rock,  of  the 
English  Geologists,  and  the  shelly,  and  arenaceous 
limestones.  The  following  are  the  contained  fossils ; 
Saurian  animals,  two  or  three  species  of  testudo, 
several  offish,  two  or  three  of  insects,  Crustacea, 
ammonites,  nautilites,  belemnites,  trochus,  voluta, 
turbo,  turritella,  rostellaria,  ampullaria.  natica. 


239 

aacella,  planorbis,  melania,  helicina,  serpula, 
modiola,  unio,  trigonia,  cardium,  cardita,  mya,  ve~ 
nus,  lutralia,  astarte,  fistulana,  mytilus,  donax,  tel- 
lina,  pinna,  osirea,  pecten,  avicula,  lima,  terebra- 
tula,  chama,  plagiostoma,  gryphoea,  perna,  crena- 
tula ;  echinus,  encrinites,  coralloids  and  alcyonia  ; 
also  fossil  wood  and  vegetable  impressions. 

The  Middle  System  or  Division  of  Ooolite^  embraces 
Oxford  clay,  (clunch  clay)  sand,  calcareous  con- 
glomerates, (calcareous  grit)  coral  rag,  or  lime- 
stones with  madrepores  and  echinites — and  con- 
tains the  following  fossils,  viz. — bones  of  the  ich- 
thyosaurus, ammonites,  nautilus,  belemnites,  me- 
lania, turbo,  helix,  trochus,  rostellaria,  patella, 
serpula,  ostrea,  pecten,  cardita,  chama,  gry- 
phcea,  trigonia,  lima,  lithophaga,  mytilus,  modiola, 
avicula,  plagiostoma,  terebratula,  echinus,  cly- 
peus,  caryophillia,  astrea,  and  fossil  wood. 

The  Upper  Division  of  Ooolites  contains  the  clay 
of  Kimmeridge,  blue  and  a  little  bituminous,  the 
Portland  stone,  Purbeck  stone,  argillaceous  lime- 
stone with  shells,  alternating  with  marl  and  gyp- 
sum. 

The  list  of  fossils  follows — Ichthyosaurus,  plesi- 
osaurus,  cetacea  ;  several  species  of  fish,  ammo- 


240 

nites,  nautilus,  belemnite,  turritella,  natica,  so- 
larium, trochus,  turbo,  melania,  ostrea,  astarte* 
crenatula,  pecten,  trigonia,  venus,  modiola,  lu- 
tralia,  cardita,  cardium,  mactra,  tellina,  chama, 
nerita,  uriio,  avicula,  cyclas,  terebratula,  serpula, 
The  ammonite  triplicai  us,  and  pecten  lamellosus 
are  most  characteristic  of  the  Portland  oolite ;  and 
the  ostrea  deltoidea  of  the  Kiinmeridge  clay. 

The  beds  above  the  oolite  are  iron  sand,  green 
sand,  and  chalk  marie,  running  into  chalk,  the  last 
of  the  secondary  rocks,  approaching  upwards. 

The  IRON  SAND  FORMATION,  is  composed  of  a  se- 
ries of  strata  of  sand,  and  sandstone,  occasionally 
alternating  with  small  beds  of  clay>  loam,  marie, 
fullers'  earth,  and  ochre.  The  sand  and  sandstone 
are  siliceous,  and  coloured  by  oxide  of  iron — a 
metal  existing  in  such  quantity  in  this  formation  as 
often  to  render  it  worth  working.  This  seems  to 
spread  extensively  over  the  western  parts  of  the 
state  of  New-York,  and  to  be  noticed  by  Mr.  Ea- 
ton,(in  the  survey  of  the  district  adjoining  the  Erie 
Canal,  which  Gen.  Van  Rensselaer  employed  him 
to  take,)  as  the  ferriferous  sand  rock.  In  England 
it  is  occasionally  1000  feet  thick,  and  worked  in 
many  places  for  iron,  the  most  abundant  mineral 
of  this  rock. 


241 


The  organic  remains  are  not  numerous :  a  nau- 
tilus, fragments  of  ammonites,  belemnites,  ostreae, 
terebratuhe,  spines  of  the  echinus,  spongitae,  and 
corallines. 

GREEN  SAND  is  composed  of  Siliceous  sand, 
loose,  and  united  in  form  of  sandstone,  by  a  cal- 
careous cement,  and  containing  small  particles  of 
green  earth,whence  is  derived  the  name.  The  size 
of  the  grains  varies  from  very  small,  forming  a  fine 
grained  sancjstone,to  large,  forming  a  conglomerate 
rock.  It  is  usually  divided  from  the  iron  sand  by 
a  dark  blueish  clay,  containing  small  specks  of 
mica,  with  nodules  of  selenite  and  iron  pyrites. 

The  fossil  contents  are  beautiful.  A  few  teeth 
of  fishes  have  been  found,  and  upwards  of  150 
species  of  testacea — the  following  may  be  ennu- 
merated  :  ammonites,  nautilites,  hamites,  turrilites, 

,"*"-!      r  .  IT  •« "'  •  ?  -. 

belemnites,  varieties  of  helix,  trochus,  solarium, 
turritella,  murex,  natica,  pleurotoma,  rostellaria, 
auricula,  am  pull  aria,  planorbis,  turbo,  vivipara, 
serpula,  dentalium,  verrnicularia,  patella,  arca,cu- 
cullaea,  nucula,  trigonia,  pecten  pectunculus,  te- 
rebratula,  cardium,  venus,  cardita,  dianchora, 
corbula,  chama,  ostrea,  inoceramus,  mya,  modiola, 
perna.  The  echinus  in  several  varieties,  resem- 
bling,but  different  from,  those  found  in  the  chalk. 


242 

The  encrinital  remains  are  lew,  the  coralloids 
scarce  and  unimportant.  The  remains  of  Alcyo- 
nites  are  numerous  and  beautiful.  No  vegetable 
remains,  but  fragme  nts  of  silicified  wood. 

Many  of  these  interesting  fossils  have  been 
found  in  some  of  our  southern  states.  The  re- 
gion in  the  vicinity  of  the  Potomac  has  afforded 
many  beautiful  specimens  for  the  cabinets  of  our 
different  societies  and  of  individuals. 

By  alternations  of  sand  with  argillaceous  and 
cretaceous  beds,  until  the  latter  prevails.the  green- 
sand  passes  gradually  into  a  chalky  marie.  It 
differs  from  chalk  by  its  grey  or  mottled  appear- 
ance, and  its  lamellated  texture.  It  is  more  gritty 
than  chalk,  and  will  not  mark.  The  upper  and 
more  cretaceous  beds,  next  to  the  chalk,  contain 
fossil  remains,  similar  to  those  found  in  that  rock, 
viz.  nautilus,  inoceramus,  echinus,  alcyonia,  and 
spongia.  The  lower  beds,  which  are  also  more 
argillaceous,  have  their  peculiar  fossils ;  those  pe- 
culiar to,  and  characteristic  of  this  formation,  are 
the  ammonites,  mantelli,  mi  nut  us,  planicosta,  ro- 
stratus,  splendens,  variens :  the  nautilus,  insequalis 
elegans,  comptoni.  Hamites.  The  other  remains 
are  scaphites,  turrilites,  belemnites,  dentalium, 
vermicularia,  cerithium,  euomphalus,  patella* 


243 

terebratula,  area,  nucula,  pecten,  inoceramus,echi- 
nus,  zoophytes,  pentacrinite. 

' « 

The  rock  next  in  order  is  CHALK,  into  which  the 
marie  last  mentioned  easily  passes,  by  almost  im- 
perceptible gradations,  forming  at  first  the  chlori- 
ted  chalk,  (glauconie  crayeuse,  of  the  French) 
having  small  grains  of  chlorite  sparingly  intermix- 
ed ;  then  the  coarse  chalk,  (cr^ie  tufauj  greyish 
and  sandy,  containing  some  marl  and  hornstone,  in- 
stead of  flint,  and  finally  the  white  chalk,  the  pur- 
est of  limestone  beds,  containing  only  1  or  2  pr.  ct. 
of  magnesia,  with  more  or  less  sand. 

In  Europe,  the  Chalk  forms  an  extensive  and  in- 
teresting formation  in  what  is  called  the  great  cen- 
tral basin  of  Europe,  which  is  bounded  as  follows  : 
On  the  North  by  the  primitive  ridges  of  Russian 
Finland,  Sweden,  Norway  and  Scotland  ;  on  the 
West  by  the  chains  of  Cumberland,  Wales,  De- 
vonshire and  Brittany  ;  on  the  South  by  primary 
mountains  in  the  centre  of  France,  the  Alps,  and 
the  various  insulated  groups  of  Germany,  &c.  as 
the  Black  Forest,  the  Rhingau,  and  the  Vosges, 
the  Bohemian,  Thuringian,  Saxon,  Silesian,  and 
Carpathian  Mountains  ;  and  on  the  East  by  the 
Ural  and  its  branches.  In  this  great  tract,  thus 
circumscribed,  is  another  resting  on  chalk. 


244 

Chalk  in  the  upper  beds,  invariably  embraces 
nodules  of  flint  in  great  abundance.  Iron  pyrites 
exists  in  all  the  beds. 

The  organic  remains  are  confined  to  few  gen- 
era, but  many  species  ;  teeth  of  the  shark,  ammo- 
nites, scaphites,  belemnites,  trochus,  cirrus,  turbo, 
serpula  and  spirorbis,  ostrea,  pecten,  terebratula, 
magas,  plagiostoma,  dianchora,  inoceramus,  bala- 
nus,  echinites.  These  last  are  considered  as  cha- 
racteristic of  chalk,  and  equal  in  number  all  the 
other  remains  :  one  genus,  and  many  species  are 
peculiar  to  it.  Of  the  astrea  there  are  several 
species.  Of  the  zoophytes,  the  encrinus  has  se- 
veral genera  in  the  chalk.  The  alcyonia  and 
spongia  are  numerous.  The  remains  found  in 
chalk  in  England  and  on  the  Continent  of  Europe 
are  similar,  and  preserve  their  analogy  through  all 
the  different  beds.  In  the  most  ancient,  the  bones 
of  the  monitor,  of  sea  turtles,  and  teeth  and  ver- 
tebrae of  fishes  are  every  where  found. 

The  chalk  formation  has  not  yet  been  discov- 
ered in  our  country,  and  some  deny  its  existence. 
It  is  presumption  however  in  any  man  to  assert 
that  it  is  not  to  be  found  :  thus  far  the  search  for 
it  has  been  unsuccessful ;  but  when  Geologists 
shall  more  thoroughly  examine  the  structure  of 
our  continent,  it  surely  is  not  too  much  to  say,  that 


245 


is  very  possible  this  rock  may  be  found.  But  even 
should  it  never  be  discovered,  the  geological 
chain  is  still  unbroken. — We  are  not  to  expect 
precisely  the  same  rocks  in  all  countries,  nor  are 
we  even  to  expect  geognostic  equivalents  for  every 
individual  rock  that  may  be  absent — since,  as  has 
before  been  stated,  upon  high  authority,  one  form- 
ation may  represent  many  others.  At  any  rate, 
Chalk  must  retain  an  important  place  in  all  sys- 
tems or  outlines  of  Geology. 

It  forms  in  Europe  a  very  remarkable  and  con- 
spicuous formation,  and  because  we  do  not  find  it 
on  our  continent,  are  we  therefore  to  discard  it 
from  systems?  As  well  might  we,  in  treatises  on 
governments,  discard  the  despotic,  or  the  mon- 
archical, because  in  the  United  States,  we  find 
only  the  republican.  No  individual  should  arbi- 
trarily introduce  new  names  into  any  science, 
without  the  most  profound  study  and  reflection 
upon  the  consequences  :  nor  has  any  one  the  pri- 
viledge  of  discarding  certain  terms  upon  his  own 
authority.  Most  persons  are  willing  enough  to 
listen  to  and  examine  proposed  or  suggested  no- 
velties, which  may  be  correct,  or  not.  It  is  per- 
haps better  to  retain  an  old  name  that  is  not  strict- 
ly scientific,  than  to  deluge  us  with  new  terms  to 


33 


246 

perplex  the  student  without  gaining  any  other 
object. 


It  will  be  observed  that  the  Secondary  Rocks 
compose  an  extensive  and  valuable  portion  of  our 
Union.  The  country  of  the  Mississippi,  which  is 
but  a  portion  of  an  immense  region  of  valley  or 
flat  country,  that  extends  from  the  Gulph  of  Mexi- 
co, north-easterly  to  the  Atlantic,  and  north-wes- 
terJy  to  the  Pacific  Ocean,  is  of  secondary  forma- 
tion. Extending  for  hundreds  of  miles,  it  enjoys 
at  one  extreme  the  brilliant  sunshine  of  the  south, 
and  at  the  other  the  frozen  rigors  of  winter.  It 
possesses  a  fertile  region,  decked  with  all  the 
beauties  of  vegetation,  and  offering  the  choicest 
grains  and  fruits  and  flowers  to  the  occupant. 
The  mild  beauty  of  its  elevations,  crowned  with 
oak  and  ash  and  hickory,  the  luxuriant  fertility  of 
its  vales  bearing  abundance  of  grain,  and  watered 
by  large  and  picturesque  rivers,  presents  to  us 
some  of  the  finest  and  sweetest  scenery  of  our 
country. 

As  no  section  of  our  Union  is  more  productive 
Jban  our  Secondary,  so  none  is  more  blessed  with  * 
Contentment,  and  prosperity. 

Its  soil  is  fertile,  and  its  rocks  rich  in  treasures. 


247 

The  TERTIARY  FORMATIONS  commence  where  the 
Secondary  ends,  viz.  at  Chalk.  It  may  be  consider- 
ed as  a  good  rule,  that  all  rocks  older  than  the  old 
red  sandstone,  are  primary — all  those  between  the 
red  sandstone  and  chalk  are  secondary,  and  those 
above  chalk,  tertiary.  Volcanic  rocks  and  Alluvia 
are  of  separate  and  distinct  classes  from  each  and 
all  others. 

The  tertiary  formation  is  composed  of  different 
compounds,  in  which  lime  and  sand  and  clay  are 
the  chief  materials.  It  is  but  a  few  years  since 
these  strata  have  been  separated  from  the  alluvia. 
It  was  first  noticed  in  the  vicinity  of  Paris  that 
they  were  too  large  and  regular  to  be  of  alluvial  de- 
posit, and  the  researches  of  Cuvier  and  Brong- 
niart  established  them  as  belonging  to  a  new  class 
of  formations.  The  accurate  observations  of  Mr. 
T.  Webster,*  then  occupied  in  making  drawings 
for  the  splendid  work  of  Sir  H.  Englefield  on  the 
Isle  of  Wight,  soon  determined  that  the  beau- 
tiful island  was  not  only  of  tertiary  formation, 
but  that  it  was  precisely  similar  to  the  tertiary 


*The  accuracy  of  this  accute  Geologist  has  lately  been  ques- 
tioned in  one  of  the  most  learned  periodical  journals  in  Eng- 
land. But  it  must  be  evident  to  Geologists  that  the  author  oi 
the  attack  (Dr.  Fitton)  is  often  in  error,  and  contradicts  him- 
self, so  as  in  a  great  measure  rather  to  corroborate  the  state- 
ments of  Mr.  Webster,  than  to  disprove  them. 


24U 

tbrmations  of  France.  To  this  gentleman  and 
to  Mr.  Buckland  we  owe  the  first  scientific  de- 
scription of  these  formations  in  England. 

The  North  of  Germany,  to  some  distance  from 
the  shores  of  the  Baltic — the  great  valley  of 
Switzerland,  near  the  Lake  of  Constance — some  of 
the  Subappenine  hills  in  the  valley  of  the  Po,  and 
accompanying  the  shores  oi  the  Adriatic  to  Otran- 
to — Sicily,  Dalmatia  and  parts  of  Greece  exhibit 
similar  beds,  in  which  we  find  the  same  fossils  and 
the  same  compounds. 

This  class  is  remarkable  for  the  beauty  and 
variety  of  its  organic  remains. 

As  these  formations  are  composed  of  an  indefi- 
nite number  of  strata  succeeding  each  other  with- 
out any  very  determinate  order,  we  are  naturally 
led  to  expect  a  diversity  of  combinations  and 
names. 

The  first  division  of  this  class  was  made  by 
Cuvier  and  Brongniart,  who  enumerate  the  fol- 
lowing in  France. 

Plastic  clay,  with  sand,  (argile  plastique)  fresh 
water  deposit. 

Coarse  marine  limestone,  (cakaire  grassier,) 
with  marine  sandstone,  or  (gres  marine  in/ercur) 
marine  deposit. 


,  \ 


Siliceous  limestone,  (calcaire  silicieux)  not  ascer- 
tained.) 

Gypsum  and  marie  containing  bones  of  ani- 
mals, (marnes  du  gypse  d'  ossemens,)  Fresh  water 

and  marine. 

Marine  marl,  abounding  in  bivalve  shells  ;  the 
superior  layers  containing  oyster  shells  in  abun- 
dance. (Marine.) 

Sandstone  and  sand,  without  shells,  (not  deter- 
mined.) 

Upper  marine  sandstone,  (gres  marine  superieur) 
marine. 

Millstone  or  Buhrstone  without  shells,  (muliere 
sans  coquilles,)  not  determined. 

Upper  fresh  water  formation,  millstone,  flint, 
and  limestone,  (terrein  (Teau  douce  superieur, 
menliere  silex  et  calcaire,}  Fresh  witer. 

These  are  supposed  to  be  alternate  deposits 
from  the  salt  water  of  the  ocean  and  of  fresh  wa- 
ters of  lakes. 

The  plastic  clay  rests  on  the  chalk.  It  is  white, 
grey,  yellow,  red  and  black,  containing  a  layer  of 
sand,  and  a  few  very  organic  remains.  The  clay 
is  tenacious,  unctuous,  and  slightly  siliceous,  and 
is  used  in  the  manufacture  of  pottery  and  porce- 
lain. The  sand  has  all  varieties  of  color. 


250 

The  coarse  marine  limestone  and  marine  sandstone 
composed  of  several  distinct  strata.  The  first  a 
coarse  sandy  limestone  containing  green  particles, 
and  many  shells  retaining  much  lustre,  and  differ- 
ing from  existing  species.  The  following  are  en- 
umerated :  nummulites,  madrepora,  astrea,  car- 
yophillia,  fungites,  cerithium,  lucina,  cardium,  vo- 
luta,  crassatella,  turritella,  ostrea. 

The  second,  greyish  yellow  limestone,  partly 
oolitic,  and  containig  cavities  filled  with  loam, 
sand,  and  flint.  It  contains  nearly  all  the  500 
different  species  of  bivalves  found  at  Grignon  : 
the  following  shells  may  be  mentioned  cardita, 
orbitolites,  turritella,  terebellum,  calyptrea :  pec- 
tenculus,  citherea,  miliolites,  cerithium. 

The  third  is  less  abundant  in  fossil  varieties — 
miliolites,  cardium,  lucina,  ampullaria,  cerithium, 
corbula.  The  second  and  third  sometimes  em- 
brace a  sandstone  containing,  among  others,  the 
following  shells — calyptraea,  oliva,  ancilla,  voluta, 
fusis,  cerithium,  ampullaria,  nucula,  cardium,  ve- 
nericardia,  cytherea,  venus,  lucina,  ostrea. 

The  fourth  embraces  marls,  hard  and  soft,  and 
calcareous  sand,  occasionally  agglutinated,  and 
containing  layers  of  hornstone,  and  crystals  of 
quartz,  calcareous  spar,  and  duor  spar,  with  very 
few  fossils. 


The  siliceous  limestone  without  shells  occurs  always 
on  the  same  level,  and  alongside  of  the  preceding. 
It  consists  of  strata  of  white  limestone,  and  of 
grey,  or  compact,  or  granular  limestone,  penetra- 
ted by  silex,  which,  in  different  shapes,  tills  the 
cavities.  It  has  no  fossils*  It  seems  to  be  only  a 
part  of  the  preceding  rock. 

The  gypsum  formation,  and  the  marine  marl  forma- 
tion, are  treated  of  together :  being  gypsum,  and 
beds  of  clay  marl  and  calcareous  marl,  in  a  regu- 
lar succession,  when  all  are  present.  The  gyp- 
sum constitutes  the  greatest  mass,  occurring  in 
longish  or  conical  bodies,  and  not  in  extensive 
fields.  Montmatre,  in  Paris,  is  an  example,  and 
there  three  beds  are  placed  over  each  other. 
The  first,  contains  alternate  layers  of  gypsum,  cal- 
careous marl,and  argillaceous  marl:  sea  shells  are 
found  in  it — as  are  fresh  water  shells  in  the  white 
marl.  The  second  has  more  beds  of  marl  than 
the  firsthand  contains  sulphat  of  stroritian  and  fos- 
sil fishes.  The  third  is  the  most  extensive,  and 
contains  many  beds  of  marl.  The  quarries  in 
this  upper  gypsum  afford  those  remarkable  skele- 
tons and  bones  of  unknown  birds  and  quadrupeds. 
The  following  fossils  are  found  in  these  united 
formations.  Palgeotherium,  magnum,  medium. 


252 

crassum,  curtum,  and  minus.  Anaplotherium, 
commune,  secundarium,  medium,  minus,  minimum. 
A  pachidermatous  animal  allied  to  the  hog.  Ca- 
ms parisiensis.  Three  or  four  species  of  birds. 
Trionix  parisiensis,  and  another  tortoise.  A  sau- 
rian animal,  allied  to  the  crocodile.  Three  or 
four  species  of  fishes.  Cyclostoma,limneus,planor- 
bis,  spirorbis,  cerithium,  cytherium,  ampullaria, 
cardium,  nucula,  ostrea,  cancer. 

Sandstone  and  Sand  without  shells  rests  on  those 
already  described,  in  strata  of  considerable  thick- 
ness. 

The  Upper  Marine  Sandstone  and  Sand  varies  in 
composition,  and  color  arid  compactness,  being  a 
greyish,  or  red  sandstone,  sometimes  argillaceous, 
sometimes  calcareous.  This  sandstone  contains 
fossils  differing  from  those  found  in  the  sandstone 
formerly  mentioned,  viz.  olivia,  cerithium,  pectun- 
culus,  crassatella,  donax,  citherea,  corbula,  ostrea, 
melania  ?  fusus  ? 

Millstone  without  shells  embraces  millstones,  sand, 
iron  shot,  and  a  clay  marl,  greenish,  reddish,  or 
whitish.  It  seems  to  be  only  a  portion  of  the  fol- 
lowing division.  The  millstone  is  a  quartz  with 


253 

many  irregular  cavities,  traversed  by  reticulated 
siliceous  fibres,  and  sometimes  filled  with  ochre, 
clay  or  marl.  There  are  no  organic  remains  in 
the  millstone. 

The  Flint  and  Siliceous  Limestone  formation  con- 
sists of  these  two  substances,  independent  of 
each  other,  or  intimately  united.  The  limestone 
most  common  is  nearly  pure,  often  embracing  flint, 
of  which  however  large  masses  are  rare.  The 
limestone  is  white  or  yellowish,  and  whatever  may 
be  its  original  hardness,  it  softens  by  exposure, 
and  forms  a  manure  for  the  agriculturalist.  The 
essential  character  of  the  formation  is  the  contained 
multitude  of  fresh  water  and  land  shells,  nearly  all 
of  which  belong  to  genera  now  inhabiting  moras- 
ses ;  but  no  marine  shells,  except  when  in  imme- 
diate contact  with  the  marine  formation.  The  fol- 
lowing belong  particularly  to  the  upper  fresh  wa- 
ter formation.  Cyclostoma,  potamides,  planorbis 
limneus,  bulimus,  pupa,  helix,  dycotyledons  sili 
cified,  arundo.  No  bivalve  occurs  among  the 
number. 

It  has  been  justly  observed  that  the  Plastic  clay, 
limestone,  gypsum,  sandstone,  and  flint  and  silice- 
ous sandstone,  seem  well  characterised ;  and  that 
34 


254 

the  terms  fresh  water  and  salt  water  formations 
might  perhaps  be  supplied  by  more  appropriate 
names.  •  The  hypothesis  whence  these  names  are 
derived  seems  supported  by  the  organic  remains 
of  the  strata. 

Of  th  e  Tertiary  Formations  in  England  we  have 
an  elaborate  description  by  Messrs.  Conybeare 
and  Phillips.  They  name  four,  viz.  the  Plastic 
sand  and  clay,  resting  upon  which  is  the  London 
clay,  and  over  this  the  fresh  water  formation,  and 
the  upper  marine  formation. 

The  Plastic  Clay  is  formed  of  an  indefinite  num- 
ber of  beds  of  sand,  clay  and  gravel,  alternating 
without  order.  Mr.  Webster  remarked  the  simi- 
larity of  this  iormation  to  that  of  Paris.  The  sand 
of  Alum  Bay,  in  the  Isle  of  V\  ight,  exhibits  every 
variety  of  color.  The  clay  is  laminated,  and  of  va- 
rious colors  and  purity,  offering  the  several  kinds 
of  clay  for  the  arts.  There  are  few  minerals :  iron 
pyrites,  selenite,  gypsum,  and  a  few  spangles  of 
mica.  The  organic  remains  are  not  numerous 
nor  regular,  being  found  indiscriminately  in  the 
clay,  sand,  and  pebbles.  The  following  are  the 
/usually  contained  fossils,  murex,  infundibtilum. 


255 

uehthium,  turritella,  planorbis,  astrea,  peetunculus, 
mya,  cytherea,  cjclas. 

The  London  clay  is  so  called  from  its  forming  the 
substratum  of  London  and  its  environs.  It  is  a 
tough,  bluish  or  blackish  clay,  varying  in  its  char- 
acters ;  some  strata  partaking  of  the  nature  of  marl. 
The  lower  parts  frequently  run  into  a  siliceous 
sandstone. 

It  may  be  stated  to  be  an  extensive,  argillace- 
ous deposit,  embracing  subordinate  calcareous 
beds,  occasionally  passing  into  solid  rocks,  or  va- 
ried in  aspect  by  an  accidental  mixture  of  sand 
arid  calcareous  matter  with  the  clay. 

In  its  relations  and  fossils  this  is  supposed  to 
approximate   nearly   to    the    cakaire    grassier   of 
Paris.     It  contains  iron  pyrites,   amber,  selenite, 
and  lignite  with  the  woody  fibre. 

The  fossils  are  interesting  and  numerous.     The 
crocodile   and  the  turtle,  and  several  species  of 
fish  are  found.     Zoopytes  are  rare.  The  vegetable 
remains  are  numerous  and  beautiful.     In  the  island 
of  Sheppey  alone  upwards  of  700  varieties  of  fos- 
sil  fruit  have    been    observed.     The   following 
shells  are   mentioned  viz :   ammonites,  nautilites, 
nummulites,  seraphs,  cyprea,  conus,  terebelluiB, 


256 

auricula,  voiuta,  oliva,  ancilla,  buccinum,  melanm, 
cassis,  murex,  pleurotoma,  fusus,  rosteilaria' 
strombus,  cerithium,  infundibulum,  trochus,  sola- 
rium, turritella,  turbo,  scalaria,  ampullaria,  vivipa- 
ra,  natica,  ostrea,  pecten,  pectunculus,  avicula, 
modiola,  nucula,  area,  chama,  mya,  lingula,  solen, 
cardium,  cardita,  isocardia,  venericardia,  venus* 
corbula,  serpula,  dentalium,  teredo. 

The  fresh  water  formation,  in  general  terms,  con- 
sist of  marie,  argillaceous  limestone,  and  sand? 
crossed  by  calcareous  spar.  It  contains  no  gyp- 
sum, which  is  so  plentiful  and  abundant  in  re- 
mains, in  the  French  corresponding  beds.  This 
formation  has  been  seperated  into  the  upper  and 
lower  divisions. 

The  latter  consists  in  a  series  of  beds  of  sandy, 
argillaceous,  and  calcareous  marls,  containing  a 
coaly  matter.  Some  of  them  seem  to  be  wholly 
composed  of  comminuted  fresh  water  shells,  con- 
tainining  some  that  are  entire,  among  them  are  the 
lymneus,  planorbis  and  cyclostoma,  helix  ?  and  my- 
tilus? 

The  upper  division  is  an  extensive  calcareous 
bed,  of  yellowish  white  marl,  that  is  soft,  but  in- 
cludes harder  and  more  durable  masses.  It  con- 
tains veins  of  cabonat  of  lime— The  organic  contents 


257 

are  found  in  all  parts  of  the  bed,   and  consist  ex- 
clusively of  fresh  water  shells,  as  lymneus,  planor- 
bis,  helix.     Some   seeds  are  found,  and  parts  of 
coleopterous  insects. 

The  other  shells  found  in  the  entire  formation 
are  potamides,  paludina,  melanopsis,  phasianel- 
la  ?  ampullaria,  unio. 

The  upper  marine  formation  is  composed  of  sandy 
and  gravelly  deposits  enclosing  fresh  water  shells, 
and  sometimes  embracing  beds  of  shell  marie.— 
The  sand  is  sometimes  ferruginous,  and  cemented. 
It  resembles  the  corresponding  formation  of 
France.  It  contains  no  minerals.  The  following 
fossil  are  mentioned.  A  large  tooth,  fragments  of 
bones,  spongia,  alcyonia.  Most  of  the  shells 
are  recent.  Patella,  emarginula,  calyptrea,  buc- 
cinum,  murex,  cassis,  natica,  turbo,  cyprea,  scal- 
laria,  turritella,  vivipara,  voluta,  trochus,  infundi- 
bulum,  my  a,  unio,  lingula,  my  til  us  cardium, 
venericardia,  venus,  area,  astarte,  mactra,  solen 
tellina,  nucula,  balanus,  pholaa,  dentalium. 


Of  the  Tertiary  Formations  in  the  United  States, 
the  most  extensive  is  the  Plastic  Clay,  exhibiting 
its  brilliant  clays  and  sands,  with  its  beds  of  peb- 


258 

bles,  and  its  lignite.     At  Martha's  Vineyard,  where 
it  has  been  examined  by  Mr.  Hitchcock,  it  presents 

cliff200  feet  in  height,  composed  of  an  irregular 
succession  of  beds  of  clay,  sand  and  pebbles,  with 
lignite.  The  clays  are  white,  brown,  blackish, 
red  and  yellowish  of  many  shades.  The  sand  too 
has  various  colors.  The  pebbles  have  a  ferrugin- 
ous coat — The  lignite  is  well  characterised.  There 
occur  small  plates  of  silvery  mica,  and  a  small  and 
occasional  quantity  of  amber.  The  subtratum  is 
not  known. 

On  Long  Island  this  formation  is  well  marked, 
and  there  is  scarcely  a  man  on  the  island  but 
knows  that  at  the  depth  of  from  1 5  to  60  feet  char- 
red wood,  with  perriwinkle  and  other  shells  are 
found  in  beds  of  clay,  sand,  and  gravel. 

Large  quantites  of  clays  are  annually  sent  from 
Amboy,  (New  Jersey.)  and  their  use  ip  manufac- 
tures is  well  known.  The  whole  triangle  formed  by 
the  Ocean  and  the  Delaware  and  Raritan  rivers  is 
composed  of  sand,  clay  and  gravel,  alternating, 
and  occasionally  consolidated  by  a  ferruginous  ce- 
ment. It  contains  lignite  and  shells.  The  banks 
of  the  Delaware  river,  for  several  miles,  are  com- 
posed of  brilliant  sands,  with  beds  of  clay  and  lig- 
nite :  the  clay  is  white,  yellow  and  blue,  with 
shades.  This  formation  extends  southward,  skirt- 


259 

ing  the  Atlantic  through  our  southern  states.  It  has 
been  examined  at  various  points,  and  presents  the 
same  characters  at  Martha's  Vineyard,  Long  Island, 
Staten  Island,  New  Jersey,  near  Philadelphia*  at 
Cape  Sable,  and  in  Florida. 

Its  similarity  to  the  English  arid  French  Plastic 
clay  is  acknowledged  now  by  all  those  who  have 
kept  pace  with  the  rapid  strides  of  Geology  for 
the  few  last  years,  and  who  are  willing  to  ex- 
amine facts  without  reference  to  theories.  The  fol- 
lowing fossils  have  been  found.  Murex,  venus,  car- 
dium  pectunculus,  ostrea,  area,  pecten,  donax, — 
teeth  of  sharks,  crocodiles,  and  cetacea. 

The  London  Clay,  or  a  corresponding  formation 
has  been  supposed  to  exist  at  Washington,  and  to 
form  the  general  substratum  of  the  city.  It  was 
noticed  and  mentioned  several  years  ago,  as  a  mud- 
dy clay,  containing  occasional  pebbles  and  shells 
— with  trunks  and  branches  of  trees  resembling 
coal,  and  with  iron  pyrites.  The  teeth  of  sharks 
and  a  large  rib  were  many  years  ago  taken  from 
the  clay.  Mr.  Finch  has  compared  it  to  the  forma- 
tion of  Highgate  near  London. 

f          t   •:    •   'irr         »  •    1   '          .  '          .-A."-',       •}. 

The  coarse  marine  limestone  (calcaire  grossier)  and 
the  siliceous  limestone  (calcaire  silicieuse)  seem  to 


exist  in  Georgia,  judging  from  the  millstone  or  buhr 
stone  sent  from  that  state.  In  some  parts  of  this 
formation  are  cavities  are  filled  with  stalactites  or 
incrustations — in  other  places  it  abounds  in  shells, 
among  them  mactra  and  tellina  have  been  obser- 
ed,  with  madrepores  and  a  pectunculus.  Horn- 
stone  and  quartz  are  found  imbedded.  The  calcaire 
grossier  has  been  observed  by  Humboldt  in  So- 
America,  and  there  contains  ostrese,  madrepores 
and  turbinites. 

In  New  Jersey  are  several  localities  of  a  clay 
nearly  filled  with  shells — or  perhaps  more  correct- 
ly of  large  masses  of  shells  with  clay.  They  rest  on 
gravel  beds ;  and  are  used  as  manures,  under  the 
name  of  marl.  These  beds  are  immediately  under 
the  soil,  and  afford  the  remains  of  the  mastodon, 
the  crocodile,  the  shark,  the  monitor  and  cetacea : 
pectens,  terebratulae.  donax,  area,  turbinolia,  ros- 
tellaria,  ammonites,  pyrula  ;  also  lignite  and  amber. 
Similar  localities  exist  in  the  counties  of  Orange 
and  Ulster  where  bones  of  the  Mastodon  have  been 
found  :  the  pecten,  ostrea,  venus,  planorbis,  helix* 
and  voluta. 

This  seems  to  correspond  with  what  is  termed 
by  the  English  Geologists,  the  upper  fresh  water 
formation. 


261 

An  interesting  account  of  these  formations  will 
doubtless  soon  be  published  by  those  who  have 
had  more  extensive  opportunities  and  leisure  to 
examine  them.  From  a  collection  of  shells  lately 
made  in  Maryland,  the  following  have  been  de- 
scribed in  the  Journal  of  the  Academy  of  Natural 
Sciences  at  Philadelphia.  Turritella,  natica, 
oliva,  buccinum,  fusis,  fulgur,  calyptrcea,  dispotoa, 
fissurella,  ostrea,  pecten,  plicatula,  area,  pec- 
tunculus,  nucula,  venericardia,  crassatella,  iso- 
cardia,  tellina,  lucina,  venus,  cytherea,  astarte, 
mactra,  ampiiiderma,  corbula,  panopcea,  ser- 
pula,  dentalium.  In  Europe  the  isocardia  has,  I 
believe,  been  found  only  in  the  London  clay  ;  and 
the  astarte  in  the  upper  marine  formation  :  should 
these  be  considered  as  characterestic,  this  collec- 
tion of  fossils  would  indicate  their  positions  to  have 
been  the  Plastic  clay,  London  clay,  and  upper 
marine  formations. 

The  siliceous  sand  of  the  upper  marine  forma- 
tion, shifting  with  every  wind  that  blows,  is  seen 
on  many  parts  of  Long  Issand,  in  iNew  Jersey,  Vir- 
ginia and  the  Carolinas. 

In  fine,  the  whole  tract  of  country,  with  few  and 
small  exceptions,  between  the  Allegany  ridge  and 
the  ocean  is  of  tertiary  formation.  Commencing, 
certainly  as  far  north  as  Martha's  Vineyard,  per- 


j 


262 


haps  even  embracing  the  gypsum  and  sand  of  Nova 
Scotia,  it  extends  through  Long  Island,  and  New 
Jersey,  and  stretching  through  our  Atlantic  States, 
forms  a  class  corresponding  in  size  with  our  gigan- 
tic primary  and  secondary. 


Some  certain  rocks  are  usually  referred  to  a 
peculiar  class,  under  the  term  SUPERINCUMBENT  or 
OVERLYING  ROCKS.  They  are  unstratafied,  and  pos- 
terior to  the  rocks  in  connection  with  which  they 
are  found.  They  pass  almost  imperceptibly  into 
each  other,  with  a  few  exceptions  that  scarce  de- 
serve notice.  It  may  be  said  that  they  occur  as  re- 
cent secondary  rocks;  some  of  them  are  of  older 
origin,  but  there  are  no  unexceptionable  rules  for 
distinguishing  them,  and  it  is  perhaps  best  to  class 
them  together.  This  is  the  more  necessary  as 
neither  composition  nor  position  authorize  the  dis- 
tinction of  separate  families. 

The  rocks  of  this  division  occur  in  more  or  less 
extensive  localities;  and  are  by  some  considered 
as  independent  formations.  While  other  geologists 
suppose  them  universal,  as  they  are  found  forming 
tracts  in  all  countries. 

They  are  observed  in  contact  writh  every  rock 
from  granite  to  the  most  recent  secondary.  We  do 


263 

not  know  if  they  ever  rest  on  the  tertiary;  they 
have  not  been  noticed  in  that  position. 

In  granite  they  occur  in  veins.  In  the  stratified 
rocks  of  both  primary  and  secondary  classes  they 
appear  as  masses  also,  and  sometimes  even  as 
beds.  It  is  said  that  in  the  Isle  of  Skye  they  form 
strata  parallel,  and  not  connected  with  veins,  but 
alternating  with  jasper,  siliceous  schist,  and  fer- 
ruginous clay. 

These  rocks  sometimes  constitute  mountains,  or 
hills ;  and  sometimes  form  the  summits  merely. 
Mount  Holyoke,  Mount  Tom,  East  and  West  Moun- 
tains, near  New  Haven — and  the  superb  Palisa- 
does  on  the  Hudson  river  are  familiar  examples. 

They  sometimes  resemble  granite,  being  dispos- 
ed in  beds,  and  divided  into  cuboid al  masses,  which 
occasionally  become  rounded  by  the  weather,  in 
the  same  way  as  that  rock. 

They  are  sometimes  also  prismatic  and  columnar; 
of  which  the  Island  of  Staffa,  and  the  Giant's 
Causeway  are  among  the  most  splendid  examples. 
The  columns  may  be  regular,  and  in  contact  :  or 
they  may  be  irregular  in  the  same  bed  :  some- 
times they  are  so  confused  as  to  resemble  a  mere 
heap  of  broken  columns.  In  many  instances  the 
prisms  are  straight,  and  in  contact,  thus  bestowing 
a  beautiful  architectural  appearance ;  as  in  Fin- 


I 


's  Cave.  In  some  instances  the  prisms  are 
bent,  in  one  or  more  directions. 

The  form  of  the  columns  varies  from  three  the 
twelve  sides — which  are  often  so  placed  as  to  pre- 
sent an  absolute  whole,  marked  by  lines.  This 
structure  occurs  in  all  the  members  of  the  family— 
not  in  basalt  only,  as  is  frequently  supposed,  but  in 
sienite,  claystone-smd  greenstone. 

The  laminar  structure  occurs  in  this  family  :  the 
laminae  varying  from  the  thickness  of  paper  to 
very  large.  This  structure  is  found  in  all  varieties 
of  these  rocks.  The  laminae  are  parallel,  or 
transverse  to  the  columns,  when  combined  with 
the  columnar  structure. 

There  is  a  peculiar  internal  structure  in  these 
rocks,  exhibited  by  decomposition.  It  is  often  the 
case  that  a  column  or  joint  wastes  away,  so  as 
to  show,  by  successive  exfoliation,  a  spheroidal 
figure. 

Sometimes,  some  of  those  varieties  having  a 
base  of  indurated  clay,  become  changed,  by  dis- 
integration to  some  depth,  and  are  so  soft  as,  by 
many,  to  be  mistaken  for  clays. 

The  cavernous,  amygdaloidal  and  porphyritic 
structures,  are  also  seen  in  these  rocks. 

The  cavernous  is  similar  to  the  variety  occur- 


mm 


265 

ring  in  some  lavas — the  cells  being  elongated,  or 
contorted,  and  coated  with  a  vitreous  varnish. 

Occasionally  the  cells  contain  those  substances 
that  are  found  in  the  amygdaloids  ;  thus  these  two 
structures  sometimes  pass  into  each  other,  some- 
times into  the  porphyritic. 

There  are  so  many  rocks  in  this  class  that  we 
cannot  give  any  general  rules  as  to  texture  or  com- 
position. 

Indurated  clay  is  the  chief  substance  in  this 
family,  passing  into  claystone,  clinkstone  and  fel- 
spar :  the  extremes  of  this  series  are  essential  in- 
gredients. Of  the  less  frequent  constituents,  horn- 
blende is  the  most  common — varying  in  quantity 
and  in  the  size  of  the  crystals. 

In  sienite,  hornblende  forms  a  small  share  of  the 
rock  and  is  sometimes  crystallised.  In  greenstone  it 
is  very  minute  and  confused :  when  it  is  very  abun- 
dant, and  minutely  divided,  the  rock  passes  into  ba- 
salt. When  most  excessive  and  fine,  the  basalt  is 
well  marked  :  but  there  are  great  differences  of  as- 
pect. When  the  base  of  compact  felspar  or  clink- 
stone becomes  very  dark,  and  the  hornblende  near- 
ly disappears,  the  mass  passes  into  clinkstone :  and 
thus  many  dark  clinkstones  are  termed  basalt : 
thus  accounting  for  the  endless  variety  of  basalt? 
mentioned  by  authors. 


266 

The  presence   of  hornblende   thus  constitutes 
the  series  of  sienite.  greenstone  and  basalt,  also 
called    trap   rocks,  of  the  superincumbent  class. 
But  there  are  no  characters  for  distinguishing  in- 
variably the  two  latter.     In  each  the  base  is  clay- 
stone,  clinkstone,   or  compact  felspar,  united  by 
hornblende,  and    exhibiting  a  similar   structure. 
The  distinctive  character  chiefly  relied  on  at  pre- 
sent is  color:  those  rocks  in  which  the  constituents 
are  pale  whitish,  yellowish,  or  reddish,  being  sien- 
ite :  and  those  in  which  they  are  grey,  greenish,  or 
dark  colored,  being  greenstone.     Dr.  Macculloch 
proposes  that  instead  of  eolor  the  quantity  of  the 
ingredients  be  taken  as  a  guide  :  the  excess  of  the 
three  minerals  abovementioned  to  constitute  sien- 
ite ;  and  those  compounds  into  which  hornblende 
enters  in  equal  or  greater  proportion  to  be  named 
greenstone.     But  even  in  this  case  there  will  often 
be  doubt  as  to  the  nature  of  some  rocks. 

Another  mineral  often  forming  an  ingredient  in 
this  class,  is  augit,  which  is  supposed  to  have  been 
often  mistaken  for  hornblende.  It  occurs  in  the 
same  mariner  as  that  mineral,  usually  of  a  dark 
green  or  black  color.  It  is  sometimes  sparingly 
present,  and  then  the  compound  resembles  sien- 
ite :  at  others  it  so  finely  divided  that  the  rock 


267 

seems  homogeneous,  and  can  scarcely  be  distin- 
guished from  basalt.  It  has  been  proposed  to 
give  to  such  rocks  the  compound  name  of  augitic 
sienite,  augitic  greenstone,  and  augitic  basalt. 

Hypersthene  is  also  mentioned  as  an  ingredient, 
often  compounded  with  hornblende,  of  which  it  is 
a  species. 

Felspar  is  an  ingredient  in  the  porphyries,  and 
gives  to  this  rock  its  peculiar  character  :  but  it  oc- 
curs also  in  sienite  and  greenstone  without  attaching 
to  them  the  porphyritic  structure.  In  these  cases 
the  structure  is  granitic  Occasionally  the  felspar  is 
of  the  glassy  variety,  sometimes  crystallised,  at 
others  simply  occupying  the  place  of  common 
felspar. 

Mica  is  rarely  found  in  porphyries  :  still  rarer 
in  greenstone.  Quartz  too  is  found  in  greenstone 
and  porphyry — in  the  same  w&y  that  it  occurs  in 
granite,  from  which  these  compounds  are  some- 
times difficult  to  be  distinguished. 

The  minerals  found  in  these  rocks  are  mesotype, 
prehnite,  stilbite,  epidote,  calcareous  spar,  and  a 
very  few  others  occasionally. 

For  a  more  full  account  of  the  sub-divisons,  I 
refer  to  the  synopsis  of  these  rocks  at  the  close  of 
the  volume.  As  much  difficulty  has  arisen  in  dis- 


Sit 

tinguishing  the  members  of  this  class,  I  have 
deemed  it  adviseable  to  give  the  synopsis  of  Dr. 
Macculioch  with  slight  omissions,  as  it  may  aid 
enquirers  in  their  researches  on  this  class. 

1 

The  history  and  formation  of  ALLUVIAL  DE- 
POSITS is  extremely  interesting.  1  have  already 
slightly  noticed  them.  They  occur  in  various  sit- 
uations, bespeaking  different  origins. 

When  found  in  vallies,  through  which  rivers  run, 
they  usually  arise  from  the  abrasion  of  the  chan- 
nels in  which  these  flow  :  and  particularly  from 
hills  whence  their  sources  are  derived.  They 
arise  from  the  same  cause  when  they  form  exten- 
sive plains,  accompanying  the  estuaries  of  rivers  : 
or  when  filling  lakes  :  we  often  see  these  in  the 
interior  of  countries  where  the  lakes  have  been 
gradually  filled  with  alluvial,  and  dried  up 

The  waters  of  some  rivers  and  lakes  hold  lime 
in  solution,  which  is  gradually  deposited — this  is 
the  well  known  Travertine  of  Rome  ;  and  per- 
haps the  stalagmitic  rocks  of  Gibraltar  and  else- 
where. 

On  sea  shores  the  waves  cast  up  loose  materials 
formed  of  sand  and  fragments  of  shells,  on  which 


•It 


269 

plants  grow  and  add  a  soil  towards  the  completion 
of  a  bank,  that  eventually  rises  far  above  the 
water. 

At  the  foot  of  mountain  alluvial  is  formed  by 
the  daily  waste  of  the  materials,  urged  solely  by 
the  force  of  gravity,  and  the  ordinary  drainage  of 
the  surface. 

Occasionally  rocks  are  entirely  decomposed  in 
situ.  The  mass  of  constituents  thus  crumbled  to- 
gether, lie  loose — and  are  mostly  formed  of  gra- 
nite, gneiss,  or  red  sandstone. 

Thus  we  have  announced  four  kinds  of  alluvia, 
viz.  that  of  rivers  and  estuaries,  marine  alluvia, 
alluvia  of  descent,  and  untransported  alluvia.— 
Their  extent,  depth  and  form  are  various.  A  dis- 
tinct stratafication  is  often  observed.  The  parti- 
cles are  of  all  sizes,  sometimes  fine  as  sand,  and 
sometimes  many  cubic  feet.  If  they  are  round  or 
angular  depends  on  the  distance  they  have  been 
transported,  and  on  the  time  and  degree  they  have 
been  exposed  to  the  several  causes  of  waste,  and 
on  the  nature  of  the  materials. 

I  have  mentioned  before,  that  they  often  con- 
tain minerals,  of  which  tin,  gold,  and  diamonds 
are  the  most  remarkable. 


36 


270 

From  the  partial  alluvia,  which  we  can  trace  and 
account  for,  we  must  separate  the  DILUVIA,  found 
in  places  where  none  of  the  cause  abovementioned 
could  have  acted,  and  which  owe  their  origin,  in 
some  cases,  to  partial  and  temporary  floods ;  in 
others  to  that  great  and  eventful  deluge  described 
by  Moses,  with  whose  account,  as  we  have  seen  in 
a  former  lecture,  so  strongly  coincide  the  dicover- 
ies  of  geology,  which  has  thus  rendered  an  unex- 
pected and  important,  though  unneeded,  support 
to  the  Sacred  History. 


We  have  thus  surveyed,  with  a  cursory  glance, 
the  different  geological  theories  accounting  for  the 
present  appearance  of  our  globe. — We  have  seen 
that  they  all  refer  to  that  general  deluge  which 
forms  so  conspicuous  an  epoch  in  the  history  of  our 
planet.  We  have  observed  that  the  great  waters 
covered  our  earth — and  have  noticed  its  gradual 
subsidence,  or  the  elevation  of  the  land.  We  have 
seen  the  retiring  waters  forming  vallies — have  fol- 
lowed the  divisions  of  land — and  examined  the 
Alpine  district  of  tnountains,  the  lowland  plains, 
and  the  bottom  of  the  sea. 

We  have  also  examined,  at  least  mentioned,  all 

known  rocks — from  the  primary,  formed  before  tho 

. 


271 

existence  of  animal  or  vegetable  organization,  to 
the  secondary,  which  contain  the  organic  remains 
of  generations  passed  away,  and  which  have  been 
termed  the  medals  of  nature  : — to  the  tertiary 
which  was  last  produced,  and  the  alluvia  that  is 
daily  deposited  at  the  present. 

We  have  also  noticed  the  causes  now  operating, 
and  changing  the  surface  of  our  planet,  viz.  the 
action  of  the  elements,  water  more  particularly,  and 
the  formation  of  peat  and  of  coral  reefs,  and  have 
examined  the  agency  of  volcanoes  and  earth- 
quakes. And  in  so  doing,  have  superficially  tra- 
ced the  outlines  of  geological  science.  The  de- 
scription and  history  of  the  various  mineral  con- 
tents of  rocks  do  not  come  within  my  duties,  but 
belong  to  mineralogy. 

Should  I  be  asked  for  a  book  of  reference  con- 
taining the  elements  of  geology,  I  must  answer  that 
I  know  of  no  work  that  is  fit  for  a  beginner  in  the 
study.  Humboldt,  Macculloch,  Conybeare  and 
Phillips,  and  Bakewell,  all  presuppose  too  much — • 
and  are  calculated  for  the  perusal  of  geologists, 
rather  than  students.  Their  works  however  may  be 
advantageously  consulted.  The  various  periodicals 
of  the  United  States  contain  more  or  less  informa- 
tion on  this  subject — among  others  I  cannot. refrain 
from  noticing  a  little  and  unpretending  pamphlet 


272 

occasionally  published.  <;  The  Annals  of  the  Ly- 
ceum of  Natural  History,  of  New-York,"  a  so- 
ciety that  is  actively  and  honorably  engaged  in  ex- 
amining and  elucidating  the  natural  history  of  our 
country.  Nor  can  I  omit  to  mention  the  Journal 
of  the  Academy  of  Natural  Sciences  of  Philadel- 
phia :  Nor  the  American  Journal  of  Science,  so 
ably  conducted  by  Prof.  Silliman. 

I  am  as  sensible  as  any  ,of  you  can  be  of  the  de- 
ficiencies and  imperfections  of  this  course :  but  I 
make  no  apology,  conscious  of  your  being  all 
aware,  that  no  subject,  no  scientific  subject,  can 
be  properly  treated  of  and  condensed  into  four 
or  six  lectures. 

We  might  have  passed  our  hours  with  more 
amusement,  but  then  we  must  necrssaril)  have  de- 
parted from  the  dry  detail  of  this  science. 

I  regret  that  more  time  was  not  allowed  to  en- 
large upon  and  illustrate  the  real  value  and  utility 
of  this  science.  And  if  in  my  Lectures  I  have  failed 
to  render  the  study  of  Geology  interesting,  I  have 
the  candor  to  acknowledge,  and  sincerelv  wish 
you  all  to  believe,  that  the  fault  lies  not  in  the 
subject,  but  in  the  person  who  has  the  honor  to 
address  yon. 


u  A  ,1 


To  facilitate  the  study  of  Geology,  a  Synopsis 
of  each  individual  Rock  is  here  added,  affording  a 
view  of  the  different  compounds  that  may  be 
classed  respectively  under  each  head. 

SYNOPSIS  OF  GRANITE, 

First  Division. 
Of  two  ingredients. 

A.  Felspar  arid  mica. 

B.  Quartz  and  felspar. 

a.  An  uniform  mixture  of  these  ingredients. 

6.  The  quartz,  or  felspar,  or  both,  imperfectly 
crystallised,  and  influencing  each  other's  forms. 
Graphic  granite. 

C.  Quartz,  arid  hornblende. 

D.  Felspar  and  hornblende. 

a.  Large  grained,  or  the  hornblende  crystallised. 

b.  An  uniform  granular  mixture  :  the   ingredi- 
ents varying  materially  in   their  sizes  and  pro* 
portions. 

c.  Intimately  mixed,  so  as  to  be  nearly  undis- 
tinguishable. 


275 

Second  Division. 
Of  three  ingredients. 

A.  Quartz,  felspar  and  mica. 

a.  An  uniform  mixture  of  the  ingredients. 

b.  The  same  with  additional  crystals  of  felspar 
embedded,  porphyritic  granite. 

c.  ith  two  kinds  of  felspar,  the  common  and 
glassy. 

</.  The  quartz,  or  the  felspar,  or  the  mica,  or  all 
of  them  crystallised. 

B.  Quartz,  felspar  and  hornblende. 

a.  Large  grained.     The'sienite  of  some  mine- 
ralogists. 

b.  Small  grained,  and,  like  D.   b.  div.  1st,  often 
resembling  the  greenstones  of  the  trap  family,  by 
which  name  some  mineralogists  have  also  distin- 
guished it. 

C.  Quartz,  felspar  and  actynolite. 

D.  'Quartz,  felspar  and  chlorite. 

E.  Quartz,  felspar  and  talc. 

F.  Felspar,  hornblende  and  mica. 

This  variety  occurs  in  the  same  manner  as  D. 
div.  1st,  but  is  rare. 

V*    *''  '    «•---'  i       »^>i »-«-,.      •.•:•.'•  ^     ,\-  '    T    'J*i{ 

Third  Division. 
Of  lour  ingredients. 

A.  Quartz,  felspar,  mica,  and  hornblende  :  the 


276 

sienite  of  some  writers.     It  passes  into  var.  A.  div. 
2d,  or  into  common  granite. 

B.  Quartz,  felspar,  mica,  and  compact  felspar. 
This  is  similar  to  the  foregoing,  the  last  substance 
being  accidental. 

C.  Quartz,  felspar,  mica,  and  actynolite. 

D.  Quartz,  felspar,  hornblende  and  chlorite. 

E.  Quartz,  felspar,  hornblende  and  steatite. 

F.  Quartz,  felspar,  mica,  and  porcelain  clay. 

SYNOPSIS  OF  GNEISS. 

First  Division. 

Of  regular  composition,  containing  at  least  three 
of  the  four  minerals,  quartz,  felspar,  mica  and 
hornblende. 

First  Sub  Division. 
Granitic,  large  grained,  resembling  granite. 

A    Quartz,  felspar,  and  mica. 

B.  Quartz,  felspar  an<l  hornblende. 

C    Quartz,  felspar,    mica    and    hornblende. 
Second  Sub- Division. 

Schistose,  fine  grained. 

A.  White  felspar  and  quartz,  in  minute  grains 
intimately  mixed,  with  rare  scales  of  mica.  The 
position  of  the  mica  determines  the  foliated  struc- 
ture, often  so  indistinct  that  this  variety  is  mis- 
taken for  quartz  rock. 


277 

'V 

B.  The  same  compound  with  mica  in  abun- 
dance resembling  micaceous  schist. 

C  The  mica  so  abundant  as  to  form  continuous 
laminae ;  sometimes  mistaken  for  micaceous  schist. 

D  A  schist  of  foliated  mica,  with  interspersed 
and  large  irregular  crystals  of  felspar ;  the  quartz 
scarcely  discernable. 

E.  An  undulated  coarse  schist,  consisting  of 
large  grains  ot  felspar  arid  of  quartz  closely  pack- 
ed, and  connected  by  the  smallest  possible  quan- 
tity of  mica. 

All  schistose  divisions  present  transitions  from 
gneiss  into  quartz  rock  and  micaceous  schist. 
Third  Sub-Division. 

Laminar — the  ingredients  forming  distinct  la-* 
minae. 

A.  Quartz  and    felspar   in  alternating  laminse  : 
belonging  perhaps  with  D.  to  the  3d  division. 

B.  Quartz,  felspar  and  mica,  simply  alternating, 

C.  Quartz,  felspar  and  hornblende  disposed  in 
the  same  manner. 

D.  Felspar  and  hornblende  in  alternating  la- 
minae. 

E.  Quartz,  mica  and  hornblende ;  the  two  latter 
in  one  laminfa. 


278 

Second  Division. 

Of  irregular  composition;  consisting  of  com  pact 
felspar  united  to  some  or  all  of  the  ordinary  ingre- 
dients of  gneiss. 

A.  Compact  felspar   and  hornblende,  occuring 
also  as  a  variety  of  hornblende  schist. 

B.  Compact  felspar  and  quartz,  in  various  pro- 
portions. 

C.  Compact  felspar  and  chlorite. 

D.  Compact  felspar,  quartz  and  mica. 

E.  Compact  felspar,  quartz,  and  hornblende,  or 
mica  superadded. 

F.  Compact  felspar  superadded  in  various  ways 
to  any  of  the  preceding  varieties  of  gneiss,  con- 
taining common  felspar  also. 

Third  Division. 

Of  irregular  composition  ;  being  either  deficient 
in  the  number  of  ingredients,  or  containing  some 
substance  not  included  in  the  definition  of  gneiss, 

A.  Quartz  and  felspar,  laminar  and  granular  at 
the  same  time ;  the  foliated  disposition  resulting 
from  the  crystalline  position  of  the  felspar. 

B.  Hornblende  and   felspar,  foliated  and  some- 
times imperfectly   schistose.     Analogy   and   geo- 
logical connection  claim  here   a   place  for  this 
rock,  which  is  by  some  considered  as  primitive 


279 

greenstone,  by  others  as  hornblende  schist,  under 
which  head  it  will  be  found. 

C.  Felspar  and  mica. 

D.  Felspar  and  clay  slate. 

E.  Felspar  and  chlorite  schist. 

F.  Felspar,  quartz  and  chlorite  schist. 

G.  Felspar,  quartz  and  clay  slate. 
H.  Felspar,  quartz  and  talc. 

I.  A  granular  mixture  of  felspar  and  quartz  in 
one  lamina,  and  clay  slate  in  another. 

K.  The  same  with  chlorite  schist  instead  of  clay 
slate. 

L.  The  same  with  greywacke  schist. 

M.  Compact  quartz  with  embedded  grains  of 
felspar  in  one  lamina,  and  the  same  schists  in  the 
other. 

N.  Schistose  felspar  containing  crystals  of  horn- 
blende interspersed. 

O.  Actynolite  occupying  the  place  of  horn- 
blende 

P.  Compact  felspar,  argillaceous  schist,  and  any 
one  or  more  of  the  other  ingredients  of  gneiss. 

SYNOPSIS  OF  MICACEOUS  SCHIST. 

First  Division. 
Consisting  of  mica  and  quartz. 


f 

280 

First  Sub-Division. 
Simply  laminar  or  foliated. 

x     t7  J 

A.  Formed  of  mica,  continuously  laminar,  with 
the  smallest  possible  addition   of  laminar  quartz. 

B.  The  preceding  reversed  as  to  ingredients. 

C.  The   continuity  of    mica  broken,  and  the 
quartz  granular. 

D.  The  mica  greenish  and  more  tender ;  ap- 
proximating to  chlorite  schist. 

E.  The  mica  grey,  but  tender ;  approximating 
to  talcose  schist. 

F.  Similar  to  the  preceding  two  ;  passing  into 
argillite. 

The  preceding  varieties  are  particularly  liable 
to  contortions. 

Second  Sub-Division. 
Granularly  laminar. 

A.  Granular  quartz  mixed   uniformly  with  mica 
in  a  parallel  position,  producing  the  laminar  frac- 
ture. 

B.  Granular  quartz,  occupying  distinct  laminae, 
separable  by  the  aggregation  of  scales  of  mica. 

C.  Granular   quartz,  divisible  into  laminae,  be- 
tween which  are  interspersed  scales  of  mica. 

D.  The  same,  with  the  scales  of  mica  so  dispo- 
sed as  to  give  the  stone  a  fibrous  appearance. 


281 

E.  The  mica  imperfectly  parallel  and  scaly,  bent 
round  the  grains  of  quartz,  giving  a  peculiar  char- 
acter to  the  rock  in  the  transverse  fracture. 

Second  Division. 
Composed  of  three  or  more  ingredients. 

A.  Many  of  the  preceding  varieties  containing 
crystals  or  concretions  of  hornblende. 

B.  The  same  containing  felspar,  and  passing  in- 
to gneiss. 

C.  Containing  chlorite  or  talc  in  addition,  and 
passing  into  chlorite  schist,  or  talcose  schist. 

D.  Irregularly  compounded  with  more  than  one 
of  the  above-named  ingredients. 

E.  Containing  carbonate  of  lime,  with  the  usual 
ingredients,  and  giving  it  the  appearance  of  gneiss. 

Third  Division. 
Conglomerated. 

Containing  superadded  fragments  of  granite, 
quartz  rock,  limestone  and  other  substances. 

SYNOPSIS  OF  ARGILLITE. 

First  Division. 

Simple  :  of  indurated  shistose  clay  alone. 
A.  Straight  fissile,  or  continuously  laminar. 


a.  With  a  straight  even  fracture  on  the  la- 
minae. 

b.  With  a  rough  and  undulated  fracture. 
The  varieties  form  roof  slate. 

B.  Imperfectly  fissile,  or  massive  slate. 

a.  Amorphous,  sometimes  breaking  more  ea- 
sily in  one  direction  than  another. 

b.  Fibrous. 

c.  Massive,  splitting  with  curved  surfaces. 

d.  Black,  imperfectly  fissile,  of  dull   earthy 
aspect. 

e.  Black,  and  so  soft  as  to  mark  paper  :  black 
chalk  or  drawing  slate.     Some  varieties  are  fissile. 

/.  Spheroidal  concretions  embedded  in  the 
laminar  varieties. 

C.  More  compact,  with  a  smooth  splintery,  or 
minutely  granular  and  splintery  fracture,  translu- 
cent on  the  edges.     Whet  slate,  or  hone. 

a.  Compact,  imperfectly  fissile,  the  fragments 
translucent,  and  much  resembling  compact  felspar 
— common  hone. 

b.  Laminar  or  scaly  ;  straight  or  undulated,  the 
fragments  translucent — used  as  hone. 

c.  Granular,  rough  :  less  translucent. 

D.  So  hard  as  to  strike  fire  easily  ;  but  the  par- 
ticles of  quartz  not  visible. 


283 

'•) 

This  is  the  flinty  slate  or  siliceous  schist  of  some 
writers. 

'•  :<&r' 
**v 

Second  Division. 

Compound :  indurated  schistose  clay,  with  some 
other  ingredient  conspicuously  mixed. 

A.  Simple  argillite  and  mica. 

a.  The  mica  extremely  thin  and  broad  :  passes 
into  micaceous  schist :  the  lustre  silky  or  plumba- 
ginous. 

b.  The  scales  of  mica  minute,  intermixed  ir- 
regularly, or  in  laminae.  The  fine  greywacke 
schist  of  some  writers. 

B.  Simple   argillite  and  talc;  of  a  greasy  feel, 
and  silky  lustre  :  passes  into  talcose  schist. 

C.  Simple  argillite  intermixed  with  chlorite. 

a.  The  chlorite  invisibly  minute,  as  if  pow- 
dery, the  fracture  dull  and  earthy. 

6,  The  chlorite  foliated,  or  scaly,  and  the 
fracture  glossy. 

These  varieties  pass  into  chlorite  schist. 

D.  Simple  argillite  with  hornblende. 

a.  The  hornblende  in  minute  scaly  crystals, 
or  irregular  grains,  or  flat  plates. 

b.  The    hornblende   fibrous  :  fascicular  :  or 
else  straight,  or  curved,  and  radiated. 

Some  varieties  of  a.  pass  into  hornblende  schist. 


I 

E.  Argillite,  A.  div.  1st,  intermixed  with  quartz, 

a.  An  uniform  mixture  of  sand  and  blue  clay  : 
imperfectly  schistose,  and  resembling  an  argilla- 
ceous sandstone. 

b  Argillite,  massive,  or  laminar,  mixed  with 
quartz  sand.  The  fine  greywacke  and  greywacke 
schist  of  some  writers. 

c.  Quartz  gravel  of  various  sizes,  similarly  in- 
termixed :  coarse  greywackes. 

F.  Argillite,  C.  div   1st,  intermixed  with  quarts 

a.  With  very  fine  grains  or  powder  of  quartz. 
Not  fissile :  fracture  sometimes   rough  and  splin- 
tery, and  often  resembling  the  fine  and  grey  varie- 
ties of  sandstone. 

b.  With  visible  grains  of  quartz  of  different 
sizes,  and  resembling  the  coarser  sandstones. 

This  also  is  termed  greywacke. 

G  Argillite,  with  embedded  particles  of  cal- 
careous spar. 

H.  Argillite,  with  embedded  felspar,  in  crystals 
or  fragments,  having  a  porphyritic  appearance. 

Third  Division. 

Of  argillite,  wi'h  two  or  more  ingredients. 
A.  Argillite  with  quartz  sand,  and  mica, 
a.  Schistose. 
£.  Massive, 


I 

Occasionally  termed  greywacke.  When  the 
quartz  is  abundant,  they  pass  into  micaceous 
sandstone. 

B.   Argillite  with  quartz  and  felspar. 

C    Argillite,  with  quartz,  felspar  and  mica. 

These  form  other  varieties  of  greywacke. 

*  .    r,  «'.  -   ...- 

Fourth  Division. 

Containing  fragments  of  the  same   or   of  other 
compound  rocks  :  of  a  conglomerate  structure. 

A.  Fragments  of  argillite  re-united. 
a.  schistose  ;  slaty. 

6.  Imperfectly  schistose  ;  or  massive. 

B.  Fragments  of  quartz  united  by  argillite. 

a.  With  simple  argillite. 

b.  With  any  of  the  compound  varieties. 

C.  Fragments  of  quartz  and  of  schistose  slates, 
united  by  var.  C.  div.  1st — massive. 

D.  Quartz,  felspar,  and  clay  slate  in  minute  frag- 
ments ;  united,  with  or  without  any  additional  ar- 
gillaceous cement. 

E.  Fragments  of  quartz  and  basalt,  cemented 
by  a  mixture  of  clay  slate  and  quartz  sand. 

F.  Fragments   of  jasper  and  clay  slate,  with 
grains  and    fragments  of  felspar   and  of    quartz, 
united  by  a  siliceo-argillaceous  base. 

38 


286 

v 

G.  Fragments  of  micaceous  schist  and  quartz, 
united  by  a  mixture  of  schistose  clay  and  sand,  or 
of  clay,  sand,  and  mica. 

H.  The  same,  containing  fragments  of  argilHte* 

This  catalogue  might  be  greatly  extended ;  the 

most    conspicuous   only  have   been  noticed.     It 

comprises  the  coarse  grey wacke  and  grey  wacke 

schist  mentioned  as  transition. 

Fifth  Division. 
Argillaceous  conglomerates. 
All  the  varieties  of  the  last  division,  with  larger 
fragments,  and  consequently  a  coarse  texture. 

SYNOPSIS  OF  SERPENTINE, 

First  Division, 
Opake. 

A.  Common  serpentine. 

«.  With  an  earthy  uniform  fracture. 
t.  With  a  splintery  fracture,  passing  to  the 
conchoidal. 

c.  The  same,  passing  to  the  granular. 

d.  With  a  granular  fracture. 

B.  Softer,  and  becoming  gradually  sectile  :  the 
potstone  of  some  mineralogists. 

C.  Passing  to  indurated   talc  ;  the  potstone  of 


287 

others,  and  mentioned  under  the  head  of  talcose 
schist. 

The  usual  colour  of  these  varieties  are  green* 
black,  brown,  red,  and  purple  of  all  tints ;  yellow, 
pink,  lilac,  and  pale  grey  are  more  rare.  The 
variations  and  admixtures  of  these  in  clouds,  spots, 
and  veins  are  infinite. 

Second  Division. 
Translucent. 
A.  Noble  Serpentine. 

a.  Foliated  and  splintery. 

b.  Conchoidalor,  splintery  conchoidal. 

SYNOPSIS  OF  PRIMARY  LIMESTONE. 

First  Division. 
Simple. 

A.  Crystalline. 

a.  Very  large  grained,  with  lamellae  straight 
or  curved. 

b.  Large  grained,  the  crystals  appearing  to 
have  compressed  each  other,  as  in  coccolite. 

c.  Middle  sized  grain — Parian  marble  &c. 

d.  Finely  granular,  saccharine,  and  firm  or 
loose — the  marble  of  Carrara,  &c. 

e.  Finely  granular  and  compacted,  becoming 
splintery. 

/.  The  crystals  so  placed  as  to  exhibit  an  im- 


,288 

perfect  shistose  structure ;  and  to  appear  as  if  it 
contained  mica. 
B.  Compact. 

a.  splintery ;  with  a  rough  granular  fracture, 

b.  Flat  splintery ;  smooth. 
aL*    c.  Splintery  and  conchoidal. 

Second  Division. 
Compound  :  of  two  ingredients. 

A.  Limestone,  with  mica  interspersed. 

a.  Foilated,  irregular,  large  granular,  resem- 
bling granitic  gneiss. 

b.  Straight   laminar,    resembling    micaceous 
schists. 

B.  Interlaminated  with  argillaceous  schist. 

C.  With  hornblende  interspersed. 

D.  With  sahlite  or  augit  of  various  colors  inter- 
spersed. 

E.  With  talc  interspersed. 

F.  With  noble  serpentine  or  steatite  so  intimate- 
ly diffused  as  to  give  a  general  color  to  the  mass. 

G.  With  garnets  diffused,   sometimes  crystallis- 
ed. 

H.  With  quartz,  in  grains  or  so  very  minute  as 
not  to  be  visible, 
I.  With  felspar. 
K.  Impregnated  with  bitumen. 


289 

r.^-j   4^'J^t'U"*"  •>  i  ^~ 

L.  With  tremolite  minutely  intermixed. 
M.  With  actynolite,  in  the  same  manner. 

Third  Division. 

Compound :  of  three  ingredients. 
A.  Limestone  with  noble  serpentine  and  mica. 
B    The  same  with  sahlite, 
C.   With  hornblende  arid  augit. 

Fourth  Division. 

Compound :  consisting  of  any  of  the  preceding 
varieties,  with  fragments  of  other  rocks,  or  of  other 
limestones. 

Conglomerates. 

A.  With   limestone  fragments   alone,  united  in 
various  ways. 

a.  The  fragments  imbedded  in  a  general  con- 
tinuous calcareoue  base. 

b.  The  fragments   agglutinated  with  little  or 
no  proper  base,  and  of  various  sizes. 

B.  Fragments  of  quartz  imbedded  in  limestone. 

C.  Fragments  of  argillite  imbedded  in  do. 

D.  Fragments  of  several  primary  rocks,  with  or 
without  fragments  of  limestone  also,  imbedded  in 
a  calcareous  base. 

Some  of  these  are  noticedagain  in  the  Synopsis 
of  Conglomerates. 


290 

SYNOPSIS  OF  QUARTZ  ROCK, 

Fiist  Division. 
Simple :  of  quartz  alone* 

A.  Pure  quartz,  similar  to  that  found  in  veins. 

a.  Hyaline. 

b.  Opake. 

B.  Pure  quartz,  compact,  laminar :  finely  fissile, 
almost  scaly ;  sometimes  laminar  and  striated. 

C.  Granular  splintery;  sometimes  passing  into 
the  compact. 

D.  Granular  :   with  large  grains  or  concretions. 

a.  Compact,  crystalline,  transparent  or  opaque. 

b.  Gravelly,   with  distinct  condensed  grains. 

E.  Arenaceous,  or  finely  granular. 

a.  Condensed  saccharine,  passing  into  var.  C. 

b.  Loose,  arenaceous,  resembling  secondary 
sandstones. 

Second  Division. 

Compound ;  of  two  ingredients. 
Of  quartz  and  felspar. 

A.  The  quartz  compact,  opaque  or  hyaline,  with 
imbedded  particles  of  felspar  dispersed  irregular- 
ly.  ,.,  ;/K;^, 

B.  The  same,  with  the  felspar  assuming  a  lami- 
nar direction :  and  predominating  more  in  one  la- 
mina than  in  another. 


291 

C.  An  uniform  rock,  more  or  less  laminar,  with 
a  fracture  between  granular  and  splintery. 

D.  The  quartz  and  felspar  both  in  distinct  grains 
and  in  various  proportions. 

a.  Highly  compacted,  and  cemented  by  silex, 
or  quartz. 

b.  Gravelly,  or  sandy,  sometimes  loose. 
Of  quartz  and  mica. 

A.  Compact  quartz,  with  scales  of  mica  inter- 
spersed. 

a.  The  quartz  opaque. 

b. hyaline,  (aventurine) 

B.  Laminar :   occasioned  by  the  position  of  the 
mica. 

a.  The  mica  in  distinct  scales,  dispersed,  but 
parallel. 

b..  The  mica  forming  distinct  laminae. 
This  latter  passes  into  mica  slate. 
Of  quartz  and  blue  schistose  clay. 

A.  The  two  substances  in  alternate  laminae. 

B.  Quartz,  arenaceous,  and  minutely  interlami- 
nated  with  clay,  similar  to  the  sandstone  accom- 
panying coal. 

C.  Quartz  sand  and  blue  clay  intimately  mixed. 
This  last  passes  into  fine  grey  wacke  schist. 


292 

Third  Division. 
Conglomerate  :  with  more  than  two  ingredients* 

A.  Quartz  sand  alone,   or  sand   and  gravel  of 
quartz  and  felspar,  with  imbedded  pebbles  or  frag- 
ments of  quartz. 

B.  The  same,  with  fragments  of  argillite. 

C.  The  same,  with  fragments  of  mica  slate,  or 
with  both. 

These  pass  into  coarse  grey  wacke. 

SYNOPSIS  OF  CHLORITE  SCHIST. 

First  Division. 
Simple:  of  Chlorite  only. 

A.  Foliated  Chlorite ;  plain  or  undulated ;  with 
minute,  or  with  large  undulations. 

Second  Division. 

Compound :  of  two  ingredients. 
Foliated  or  simple  laminar  and  alternating. 

A.  Foliated  chlorite  with  laminar  quartz. 

B. granular  quartz. 

C. laminar  felspar, 

D.  — grains  or  imperfect 

crystals  of  felspar  disposed  in  a  laminar  manner. 

Granula^ly  laminar :  mixed. 

A.  Scaly  or  imperfectly  foliated  chlorite  with 
quartz  sand. 


^    .  293 

a.  Large  grained,  with  a  rough  granular  frac- 
ture. 

b.  Small  grained,  with  a  homogeneous  aspect, 
and  often  scarcely  fissile. 

c.  The  preceding  varieties,  passing  into  grey 
wacke  schist,  and  into  argillite. 

B.  Scaly  chlorite  with    large  grains   of  quartz. 
Similar  in  structure  and  appearance  to  mica  slate 
E.  1st  div:  3d  subdiv. 

C.  Scaly  chlorite,  with  large  imperfect  crystals 
of  felspar :  similar   in  structure   to  the  preceding, 
and  resembling  granitic-gneiss. 

D.  Scaly  chlorite,  highly  compacted,   with  mi- 
nute grains  of  felspar  interspersed :  difficulty  fissile: 
occasionally  granular,  and  fibrous. 

E.  Scaly  chlorite  with  hornblende,  intermixed 
or  imbedded,  and  passing  into  hornblende  schist. 

F.  Scaly  chlorite   intermixed   with   actynolite: 
very  compact,  sometimes  fibrous,  difficulty  fissile. 

G    Scaly  chlorite  with  mica :  passing  into  mica 
slate. 

Third  Division. 

Compound :  with  more  than  two  ingredients. 
Laminar,  alternating. 

A.  Foliated  chlorite,  felspar  and  quartz. 
39 


294 

This  occurs  in  the  series  of  gneiss,  and  is  there 
introduced. 
Granularly  laminar",  mixed. 

A.  Scaly  chlorite,  quartz,  and  felspar. 

B. felspar  and  mica. 

C. hornblende    and  mica. 

D. hornblende,     quartz,  and 

green  compact  felspar. 

SYNOPSIS  OF  TALCOSE  SCHIST, 

First  Division. 
Simple:  of  one  ingredient. 
A.  Schistose  talc. 

a.  Scaly  and  foliated. 

b.  Scaly  and  semigranular. 

c.  Minutely    scaly-granular   and    indurated: 
potstone  of  some  mineralogists. 

This  variety  passes   into   serpentine,   and  ha* 
there  been  mentioned. 

Second  Division. 
Compound:  of  two  ingredients. 

A.  Talc,  and  quartz :  foliated ;  the  quartz  vari- 
ously  disposed,    and  the  rock  resembling  mica 
schist,  into  which  it  passes. 

B.  Talc,  and  foliated  or  scaly  chlorite  ;   passing 
into  chlorite  schist. 


295 

C.  Talc  and  felspar. 

D.  Talc  and  argillite :  passing  into  argillite,  un- 
der which  head  it  has  been  mentioned. 

E.  Talc  and  serpentine :  passing  into  serpentine, 

Third  Division. 
Ccmpound  :  of  three  ingredients. 

A.  Talc,  quartz,  and  felspar. 

B.  Talc,  quartz,  and  mica. 

SYNOPSIS  OF  HORNBLENDE  ROCKS. 

First  Division. 
Simple  :  of  hornblende  alone. 

A.  Very  compact,  with  a  smooth  and  dull  frac- 
ture :  the  particles  being  scarcely  discernable. 

B.  Granular,   from  small  irregular   aggregated 
crystals:  of  different  degrees  of  fineness. 

C.  Scaly,  from  an  aggregation  of  flat  crystals. 

D.  Flat,  continuously  laminar. 

E.  Fibrous. 

a    Simply  fibrous,  and  with  snort  fibres. 

b.  Fibrous  radiated. 

c.  Very  fine  fibrous  and  silky. 

F.  The  texture  so  fine  that  it  loses  its  character, 
and  passes  into  argillite. 

The  above  are  sometimes  imperfectly,  or  not  at 
all  fissile,  and  then  form  what  is  usually  named 
hornblende  rock. 


296 

Second  Division. 
Compound:  of  two  ingredients. 

A.  A  laminar  alternation  of    hornblende    and 
felspar 

a.  Continuous    platy    and    schistose,    easily 
fissile. 

b.  The  same,  but  not  at  all  fissile. 

c.  Granularly  laminar,  and  imperfectly  schis- 
tose. 

B.  The  hornblende   scaly  or  fibrous,  and  the 
felspar  arenaceous ;  not  in  distinct  laminae. 

C.  A  granular  uniform  mixture  of  the  same  in- 
gredients. 

a.  Scaly,  imperfectly  fissile. 

b.  Uniformly  arenaceous  and  mixed :  fissile. 

c.  Mottled,   the  hornblende  being  condensed 
in  patches  and  spots. 

d.  Dull :  the  ingredients  being  minutely  inter- 
mixed and  compacted. 

e.  A  very  compact,  distinct  intermixture  of  the 
two  ingredients.     Not  schistose,  nor  distinguish- 
able from  the  greenstone  of  the  superincumbent  or 
overlying  rocks. 

The  modifiations  of  aspect  and  color  are  many, 
arising  from  the  size,   and  quantity,   and  color  of 
the  grains.  These  varieties  are  the  primitive  green 
stone  of  many. 


297 

D.  The  felspar  in  excess,  the  mixture  granular. 
Entirely  different  from  any  other  hornblende  rock. 

E.  A  minute   mixture  of  hornblende  and  dark 
compact  felspar;  the  two  ingredients  scarcely  dis- 
tinguishable. 

F.  Common  hornblende schis*  with  interspersed 
particles   and  filamentous   veins  of  bright  green 
compact  felspar. 

The  two  latter  varieties  are  very  remarkable. 

G.  Hornblende  with  mica;  the  former  in  excess, 
and  the  rock  fissile.     Mixtures  of  mica  schist  and 
hornblende  differ  from  this   variety  in  containing 
quartz,  and  are  enumerated  with  mica  schist. 

H.  Hornblende  and  chlorite. 

This  is  mentioned  under  the  head  of  chlorite 

schist. 

I.  Hornblende  and  actynolite :  passing  into  acty- 

nolite  schist.     The  hornblende  is  black,  and  scaly 
or  granular ;  the  actynolite  green  and  fibrous. 

K.  Hornblende  and  indurated  talc  :  passing  in- 
to serpentine,  and  mentioned  under  that  head. 

Third  Division. 
Compound  :  of  three  or  more  ingredients. 

A.  Hornblende,  mica,  and  felspar. 

B.  Hornblende,  felspar  and  quartz. 
0.  Hornblende,  actynolite  and  mica. 


298 

D.  Hornblende,  chlorite  and  felspar. 

E.  Different  quaternary  mixtures  of  these  ingre- 
dients. 

Borne  of  these  varieties  are  also  found  under  the 
head  of  gneiss,  and  some  other  rocks.  The  size, 
proportion,  and  col  r  of  the  several  constituents 
vary  and  communicate  many  different  aspects  to 
these  rocks. 

SYNOPSIS  OF  ACTYNOLITE  SHIST. 

First  Division. 
Simple:  of  one  ingredient. 
A.  Actynolite  under  various  appearances. 

a.  Formed  of    distinct    interlaced  crystals  : 
of  various  sizes. 

b.  Formed  of  a  confused   aggregate  of  small 
crystals  :  sometimes  acicular. 

c.  The  same  passing  into  a  granular  texture, 
d   Flat  foliated. 

e.  Fibrous :  the  fibres  straight  or  undulated, 
This  division  exhi bits  some  shade  of  green,  from 
dark  bottle  green  to  sea  green :  sometimes,  rarely, 
white. 

Second  Dvision. 
Compound  :  of  two  ingredients, 

A.  Actynolite  and  felspar. 

B.  —m —---—hornblende 


I 

299 

.;<*... 

C.  Actynolite  and  mica, 

D. talc. 

E. chlorite. 

The  last  is  mentioned  also  under  chlorite  schist* 

Third  Division. 
Compound  :  of  three  or  more  ingredients. 

A.  Artynolite,  hornblende,  and  mica. 

B.  Actynolite,  hornblede,  felspar,  and  mica. 
Porphyry,  syenite,  greenstone,    and  greywacke 

are  included  in  the  synopsis  of  the  superincum- 
bent or  overlying  rocks,  and  mentioned  in  others- 

SYNOPSIS  OF  THE  OLD  RED  SAND  STONE. 

First  Division. 
Simple :  of  quartz  alone. 
A.  Sandstone  of  various  degrees  of  hardness. 

a.  Fine,  arenaceous. 

b.  Gravelly. 

c.  Compact,  splintery,  scarcely  arenaceous. 
The  last  variety  only  to    be  distinguished   from 

quartz  rock  by  its  position.    The  members  of  this 
division  are  rare. 

Second  Division. 

Compound  :  of  two  or  more  ingredients. 
A.  Quartz  sand,  mixed  with  clay.     Argillaceous 
sandstone. 


a.  Gravelly. 

b.  Fine  arenaceous. 

c.  Very  fine,  the  particles  of  quartz  invisible. 
This  last  passes  into  shale  and  argillaceous  iron 

stone. 

B.  Quartz  sand,  mixed  with  sand  or  particles  of 
felspar. 

a.  Gravelly. 

b.  Arenaceous. 

C.  Quartz  sand  with  carbonate  of  lime :    calca- 
reous; sandstone. 

a.  Gravelly. 

b.  Arenaceous  :  generally  white. 

D.  Quartz  sand  with  carbonate  of  lime  and  clay : 
argillo-calcareous  sandstone. 

a.  Gravelly. 

b.  Arenaceous. 

These  derive  their  color  from  the  clay :  when 
the  quartz  is  fine  and  in  small  quantity,  they  pass 
into  calcareous  shale  or  marie  slate. 

E.  Quartz  sand  with  mica,  and,  sometimes,  clay  : 
of  different  degrees  of  fineness. 

a.  The  mica,  scattered  throughout :  massive. 

b.  The  mica  disposed  in  a  parallel  manner, 
often  in  separate  laminae  :  schistose,   and  more  or 
less  fissile.     Schistose  sandstone. 

F.  Quartz  sand   with  indurated  or  schistose 
clay. 


+ 

301 

This  comes  under  the  head  of  argillite  (gray- 
wack)  where  it  is  also  mentioned. 

G.  Quartz  sand,  with  sand  from  the  disintegra- 
tion of  trap  rocks. 

.-• 

Third  Division. 

Containing  fragments  of  the  previous  rocks  :  of  a 
conglomerate  structure.  Red  sand  stone  conglo- 
merate, or  breccia. 

A.  The  basis  consisting  of  either  of  the  preced- 
ing fine  varieties,  except  F.  and  G,    2d  Div :  and 
containing  fragments  of  quartz  only. 

B.  Similar   basis,  with  fragments  of  one,  or  of 
all   the  preceding   rocks,    except   argillite,  with 
quartz  also. 

C.  The  same,  including  F.  2d  Div.  with  frag- 
ments of  argiJlite. 

D.  The  base  G.  2d  Div.  with  fragments  of  the 
traps. 

E.  The  same  basis  as  var.  A.  containing  frag- 
ments of  sandstone,  with  or  without  fragments  of 
preceding  rocks. 

SYNOPSIS  OF  COAL. 
Simple  :  Carbon  nearly  pure. 
A.  Burning  with  difficulty  and  without  flame  : 

anthracite,  when  perfect. 
40 


302 

This  modification  of  carbon  contains  so  little 
hydrogen  as  to  afford  neither  naptha  nor  petroleum 
on  distillation  :  of  course  it  yields  neither  flame 
nor  smoke. 

a.  Massive ;  with   a  conchoidal  shining  frac- 
ture; of  an  aspect  nearly  metallic  :  is  found  among 
primary  rocks  :  passes  into  plumbago. 

b.  Friable,  pulverulent,  or  scaly.     Rare. 

c.  Laminar :  blind  coal,  stone  coal,  Kilkenny 
coal. 

This  and  the  preceding  varieties  are  found  m 
primary  strata ;  and  sometimes  in  the  secondary, 
The  last  passes  into  common  coal. 

d.  Columnar,   or  prismatic.     Found   in    the 
vicinity  of  trap  rocks,  and  passes  into  plumbago, 

Second  Division. 
Compound  :  Carbon  and  bitumen. 

A.  Flaming,  and  burning  easily,  with   smoke, 
Common  coal;  occurs  massive  and   slaty  united. 
Several  varieties,  according  to  the  quantity  of  bi- 
tumen it  yields.     They  pass  into  bituminous  shale 
and  are  invariable  secondary. 

B.  Very  inflammable :  leaving  little  coak;  massive 
or  imperfectly  laminar :  large  conchoidal  fracture ; 
more  or  less  bright,  sometimes  dull.     Canriel  coal, 
occurs  with  the  secondary  coal — and  is  sometimes 
cut,  like  jet. 


303 

C.  Coak,  Ashes,  and  smut :  rare  and  partial  mo- 
difications, occurring  with  the  trap  rocks. 

Third  Division. 
Lignite  :  retaining  marks  of  vegetable  origin. 

A.  Jet,  or  pitch  coal,  black   amber ;  hard  and 
compact :  pitchy  lustre,  takes  a  good  polish ;  oc- 
casionally shows  the  ligneous  fibres.  Used  as  fuel. 
In  Aude,  in  France,  1200  persons  are  engaged  in 
making  ornaments  of  it. 

B.  Fibrous   brown   coal ;    bituminized   wood : 
Bovey  coal.  The  ligneous  fibre  very  distinct;  burns 
with  a  clear  flame. 

The  suturbrand  of  Iceland  belongs  to  this  varie- 

*y. 

C.  Earth  coal,  or  earthy  brown  coal ;  pulveru- 
lent, retaining  the  texture  of  wood,  though  com- 
pact :  burns  easily.    Known  also  as  Colonge  earth 
or  umber. 

D.  Moor  coal;  friable:    nearly  the  same  as 
brown  coal,  into   which  it  passes.     It  breaks  on 
exposure  to  air. 

All  the  preceding  varieties  occur  in  the  newer 
formations :  mostly  in  the  tertiary  and  alluvial, 
occupying  extensive  tracts,  in  strata  of  various 
thicknesses.  Not  much  used  as  fuel. 


304 

E.  Basaltic  coal :  basaltic  wood  retaining  the 
texture  of  wood  and  passing  into  true  coal.  Found 
in  trap  rocks. 

SYNOPSIS  OF  PEAT. 

Although  peat  does  not  properly  come  under  the 
head  of  rocks,  I  do  not  see  a  more  appropriate 
place  for  its  Synopsis  than  the  present.  It  has 
been  spoken  of  before,  and  the  following  are  the 
varieties. 

A.  Loose   or  powdery,   and   often   intermixed 
with  clay  or  sand  :  mountain  and  heath  peat. 

B.  Spongy,   imperfect,  and  containing   a  large 
proportion  of  the  roots  and  fragments  of  undecom- 
posed  vegetables. 

C.  Compact,  but  still  retaining  numerous  frag- 
ments of  vegetables,  and  passing  into  the  former. 
The  most  ordinary  variety  used  for  fuel. 

D.  Highly  compact,  with  a  total  loss  of  vegeta- 
ble texture.     Heavier  than  the   last,  and    burns 
nearly  like  coal,  with  a  considerable  flame.   More 
rare  than  the  former. 

The  varieties  B.  and  C.  are  always  in  the  same 
deposit,  and  frequently  D,  the  spoiigy  kind  being 
above  and  becoming  more  compact  below,  ex- 
hibiting the  progress  of  vegetable  decomposition  or 
the  perfection  of  peat  When  wet  in  their  natural 


305 

position  all  varieties  are  soft,  and  harden  by  dry- 
ing. 

E.  Compact  generally  flaky  wh^n  dry,  and  con- 
taining fragments,  roots,  and  trucks  oi  irees.    For- 
est peat. 

F.  When  wet,  a  mixture  of  water  and  fine  pow- 
der of  peat  :  on  drying,  very  compact.     Traiibport- 
ed  peat;  forming  fluid  bogs. 

As  long  as  vegetaton  is  kept  up,  the  peat  is  re- 
newed after  removal :  but  the  process  ceases  when 
the  vegetating  surface  is  removed,  unless  it  is  re- 
newed by  nature  or  artificial  means ;  except  in 
transported  peat. 

SYNOPSIS  OF  SHALE. 

First  Division. 
Simple. 
A.  Common  Shale. 

a.  Hard,  and  often  not  distinguishable  from 
argillite  and  graywack  :    occurs   mostly  with  old 
red  stone. 

b.  Fragile,  and  less  laminar  than  the  preced- 
ing. 

c.  Tender  and  Scaly. 

d.  Passing  into  clay. 

e.  Granular  concretionary. 
/.  Spheroidal  concretionary. 


306 

The  colors  of  these  are  grey;  when  they  change 
into  red  or  yellowish,  it  passes  into 
B  Ferriferous  shale. 

a.  Laminar,  simple,  pink,  red,  purple,  brown, 
obscure  blue,  yellow,  or  variously  mottled. 

6»  Laminar  and  short  columnar;  surfaces 
singularly  channelled  on  the  margin.  Columnar 
ironstone. 

c.  Containing  red  oxide  of  iron  in  excess,  and 
passing  into  common  iron  stone. 

C.  Adhesive  slate. 

D.  Polishing  slate  :  lighter  than  water. 

Second  Division. 
Compound. 

A.  Argillo-bituminous. 

a.  Slightly    impregnated   with    inflammable 
matter. 

b.  So  slightly  impregnated  with  bitumen  as  to 
be  combustible.    Black  and  brown.    Kimmeridge 
coal,  accompanies  true  coal. 

B.  Argillo-calcarcous;  containing  so  much  car- 
bonate of  lime  as  to  effervesce  with  acids. 

C.  Argillo-micaceous;    containing   a  consider- 
able portion  of  mica. 

D.  Arenaceo-micaceous ;  in  which  sand  enter 
in  quantities. 


307 

E.  Quartzose :  passing  into  the  flagging  sand- 
stone. 

F.  With  rounded  fragments  of  trap  and  other 
rocks  imbedded. 

G.  Alum  slate — aluminous  schist :  affording  an 
aluminous  saline  efflorescence  on  exposure  to  air, 
particularly  if  accompanied  by  heat  and  moisture. 

SYNOPSIS  OF  GYPSUM. 

A.  Granular. 

a.  Tender. 

b.  Compact — alabaster  of  artists. 

B.  Fibrous :  sometimes  dull,  often  highly  splen- 
dent. 

C.  Platy,  on  the  large  scale,  or  approaching  to 
large  granular. 

SYNOPIS  OF  SECONDARY  LIMESTONE. 

First  Division. 

Simple,  or  nearly  so ;  formed  of  carbonate  of 
lime  with  little  or  no  intermixture  of  other  earths. 
Effervesces  readily  and  burns  t©  lime  which  is  easi- 
ly slackened. 

A.  Crystaline  :  more  or  less  perfect, 

a.  Granular. 

b.  Granular  splintery. 

B.  Compact,  with  a  smooth  fracture,  more,  or 
less  glossy. 


308 

a.  Flat,  splintery. 

b.  Splintery,  and  small  conchoidal. 

C.  Thin  laminar,  scarcely  schistose. 

D.  Fibrous,  or  prismatic. 

a.  Fibrous  more   or   less   minute,  the  fibres 
simple,  parallel,  and  coalescing,  sometimes  slight- 
ly undulated.     The  lustre  occasionally  silky,  and 
the  color  white ;  forming  satin  spar. 

b.  Fibrous,  the  fibres  ramifying :    coalescing? 
and  with  a  pseudo-organic  structure. 

c.  Prismatic,  parallel  or  radiating :  the  prisms 
separable,  more  or  loss  easily:  sometimes  striated, 
and  with  an  obscure  appearance  of  joints :  madre- 
porite. 

E.  Concretionary   spheroidal.     Peastone,  roe- 
stone,  and  oolite. 

a.  With  large  spherules,  sometimes  compress- 
ing each  other. 

b.  With  moderate   sized  spherules,  roestone . 

c.  With   minute   spherules,  varying  much  in 
size,  and  sometimes  distinct :  oolites. 

d.  The  spherules   intermixed  with  irregular 
fragments :  the  Purbeck  stone. 

F.  Fragile,  or  easily  sectile. 

a.  With  a  smooth  somewhat  glossy  fracture  : 
indurated  chalk. 


*        ft  - 

309 

b.  With  an  earthy  fracture;  compact,  but  sgft : 
common  chalk. 

c.  Containing  clay :  grey  chalk. 

(/.  Earthy,  incompact:  chalk  marie. 
All  these  varieties  become  occasionally  impure, 
and  pass  into  those  of  the  next  division.  The  most 
usual  colors  are  white,  pale  grey,  dove,  dark  grey ; 
red  of  different  hues,  greyish  brown,  dark  brown, 
black. 

Second  Division. 

Compound :  containing  a  considerable  proportion 
of  other  substances.  The  nature  of  the  mixture 
ascertained  by  chemical  analysis,  but  afterwards 
recognized  by  external  characters. 

A.  Calcareous  carbonat,  with  magnesia,  chief- 
ly.    Magnesian  limestone. 

a.  Massive. 

b.  Laminar,  and  flexible  when  moist. 

B.  Calcareous  carbonat,   with  a  large  propor- 
tion of  clay  intermixed,   and  some   silica.     Lias 
limestone. 

a.  Massive :  sometimes  in  laminse  divided  so 
minutely  by  clay  or  shale,  as  to  seem  schistose. 

Some  of  them  form  a  slag  by  great  heat :  will  not 
burn  so  as  to  slack :  some  varieties,  when  sudden 
4! 


::*# 

310 

ly  wetted,  harden  like  tarras  cement,  and  may  be 
used  for  lythographic  purposes. 

b.  Concretionary  small  spheroidal;  botryoidaL 

c.  Concretionary :  large  spheroidal,  general- 
ly oblate,  and   sometimes  attached  in  pairs  by  a 
cylindrical  bar. 

C.  Calcareous   carbonat  with    a   considerable 
proportion  of  oxide  or  rust  of  iron,  as  well  as   of 
clay  and  silica.     Spheroidal,  flattened.    Often  di- 
vided internally   into  prisms    by  calcareous  spar; 
Septaria :  this  produces  water  cement  like  some  of 
the  above. 

D.  Calcareous  carbonat  with  considerable  pro- 
portions of  clay,  silica,  and  oxides  of  iron.     Oc- 
curs with  the  old  red  sand  stone. 

a.  Imperfectly  granular,  shining. 

b.  Earthy. 

c.  Smooth,   the    fracture    splintery,   or    ap- 
proaching the  conchoidal.     This  becomes  so  sur- 
charged with  other  earths  as  to  pass  into  calcare- 
ous shale,  or  marie  slate. 

E.  Carbonate  of  lime,  more  or   less  pure,  and 
intermixed  with  bitumen.     Bituminous  limestone. 

F.  Carbonate  of  lime,  intermixed    with  a  large 
proportion  ot  silica  chiefly.  It  effervesces  with  great 
difficulty,  unless  in  powder :  forms   a  slag   in  the 
fire :    passes  into  calcareous   sandstone.     When 


311 

near  to  trap  is  often  highly  indurated,  assuming  the 
character  of  chert. 

Third  Division. 

Compound  :  containing  some  visible  ingredient 
intermixed. 

A    Limestone  containing  mica. 

B.  Limestone  containing  mica  and  sand. 

These  occur  with  mica  or  micaceo-arenaceous 
shale. 

Fourth  Division. 

Containing  fragments  of  limestone,  or  of  quartz, 
or  of  diffe re  it  compound  rocks.  Conglomerated. 

A.  Containing  fragments  of  previous  limestone. 

B.  Containing  fragments  or  pebbles  of  quartz. 

C.  Containing  chert  or  agate  in  fragments. 

D.  Containing  fragments  ofargillite. 

There  are  other  divisions  of  limestone,  often 
well  marked ;  sometimes  arising  from  actual  change 
ofcharacter,  from  the  presence  of  fossil  contents,  or 
from  color :  mostly  however  these  names  are  local 
or  geographical :  the  latter  is  perhaps  the  safest, 
as  it  can  always  be  referred  to  and  known. 

SYNOPSIS  OF  SAND  STONES.— (SUPERIOR.) 
The    term  superior  sandstones  is  here  used 


•IP* 


312 


as  the  Divisions  of  these  sandstones  are  different 
from,  and  above  the  old  red  sandstone. 

First  Division. 
Simple  :  of  quartz  alone. 

A.  An  aggregate  of  grains  of  quartz,  more  or 
less  condensed,  and  varying  in  hardness. 

a.  Of  a  large  grain;  gravelly. 

b.  Fine,  arenaceous. 

The  brillancy  of  these  varieties,  which  are  al- 
most necessarily  white,  varies  according  to  the 
quality  of  the  quartz  from  wrhich  they  are  formed. 
When  highly  indurated,  their  position  alone  distin- 
guishes them  from  quartz  rock.  In  the  vicinity  of 
trap,  they  are  said  to  be  indurated  occasionally 
to  the  state  of  common  quartz. 

Second  Division. 
Compound :  of  two  or  more  ingredients, 

A.  Quartz-sand  and  carbonate  of  lime. 

a.  Large  grained,  gravelly. 

b.  Fine,  arenaceous. 
These  are  generally  white. 

B.  Quartz  sand  with  clay. 
Subdivisions  a.  and  b.  as  the  preceding. 

The  colors  vary  :  white,  ocre  yellow  of  differ- 
ent hues,  or  red,  or  grey,  or  greenish,   or  black  : 


313 

occasionally  mottled  or  striped.  The  red  varie- 
ties, and  sometimes  even  the  white  and  grey  are 
distinguishable  from  the  old  red  sand  stone,  only 
by  their  geological  position,  and  this  it  is  sometimes 
impossible  to  ascertain. 

C.  Quartz  sand  with  schistose  clay. 

The  clay  is  more  or  less  interlaminated  and  the 
rock  passes  into  shale. 

D.  Quartz  sand  with  clay  and  carbonate  of  lime. 
Subdivisions  a.  and  6.  similar  to  var.  A.  and  B.. 

E.  Argillaceous  or  calcareo-argillaceous  sand- 
stone mixed  with  bitumen. 

This  sometimes  passes  into  bituminous  shale. 

F.  Quartz  sand  with  clay  and  mica,  or  with  clay, 
carbonate  of  lime,  mica  and  red  oxide  of  iron. 

The  red  marie,  or  new  red  sand  stone  of  Eng- 
gland,  is  of  this  kind. 

G.  Quartz  sand   with  carbonate  of  lime,  mica 
and  green  earth,  called  in  England,  Kentish  rag. 

H.  Sandstone  of  various  qualities  containing  a 
large  portion  of  rust  of  iron,  which  often  forms  the 
cement  of  the  other  ingredients :  ferruginous  sand- 
stone. 

The    varieties   of  this    division,   like   those   of 

the  preceding,  when  in  comact  with  trap,  are  said 
to  pass  into  jasper  or  chert.  They  sometimes  con- 
tain pyrites,  carbonate  of  copper,  oxide  of  cobalt, 
and  oxydulous  iron. 


314 

Third  Division. 
Conglomerates. 

-TVJ?)  F 

A.  Sandstone  containing  fragments  of  quartz. 

B. nodules  of  trap. 

C fragments  of  previous 

sandstones. 

D.  Sandstone  containing  fragments  of  schistose 
clay  o»*  shale,  or  of  limestone,  or  of  both. 

E.  Sandstone   containing   flints.     English    pud- 
dingstone.     This  is  occasionally  of  a  loose  arena- 
ceous texture ;    or  is  highly  indurated.     Doubtful 
if  it  is  not  alluvial. 

SYNOPSIS  OF  CLAY 

The  clay  and  the  marie  and  sand  mentioned  in 
the  following  synopsis  belong  mostly  to  the  Tertia- 
ry formations. 

A.  Ferruginous  clay  :  scarcely  ever  plastic,  red 
or  yellow. 

B.  Fuller's   earth:  dull  green  or  grey:    semi- 
transparent,  and  crumbling  when   in  water.     Oc- 
curs in  the  upper  sandstones,  in  the  limestones  and 
new  red  marie, 

C.  Schistose   clay :    white   or   grey :    scarcely 
ever   plastic,  until  after  exposure  to  air,  when  it 
crumbles.    Pipe  clay,  often  above  the  chalk. 


D.  Indurated,  generally  in   irregular  nodules  ; 
very  refractory  in  the  fire.     Stourbridge  clay. 

E.  Plastic  clay,  potter's  clay,  of  various  colours 
and  properties.  Very  similar  to  var.  C.  New  Jersey 
clay. 

F.  Blue  clay  :   London  clay :    plastic  in  various 
degrees. 

There  are  other  varieties  of  clays,  passing  into 
different  substances — besides  lithomarge*  tripo- 
li,  &c. 

SYNOPSIS  OF  MARLE. 

A.  Simple,  or  earthy:   consisting  principally  of 
calcareous  matter. 

a.  Massive,  more  or  less  compact. 

b.  Schistose — marie  slate. 

c.  Powdery,  or  imperfectly  plastic,  with  few 
or  no  fragments  of  shells :  often  much  mixed  w  ith 
sand  and  clay. 

d.  A    congeries   of  shells  and    fragments  of 
shells,  more  or  less  pure      Shell-marie  of  agricul- 
turalists.    New  Jersey.  &c.     Some  of  the  varie- 
ties, a  &  b.  become  plaotic  on  exposure  to  air. 

B.  Bituminous   marie :   more  or   less   distinctly 
schistose.     There   is  some  obscurity  in  this   sub- 
stance, since   it  is  known  to  contain  fish,  and  it  is 


316 

said  to  be  frund  in  different  parts  of  Europe,  in 
connection  with  primary  lime-stone. 

SYNOPSIS  OF  SAND. 

A.  Quartz  alone. 

B.  and  clay. 

C. and  limestone,  or  limestone  and  clay. 

D. —  and  mica. 

E.  and    highly    ferruginous    clay,     or 

ochre,  with  other  less  important  substances  :    fer- 
ruginous or  iron  sand. 

F.  Quartz,  limestone,  mica,    and   green  earth, 
Green  sand. 

SYNOPSIS  OF  ALLUVIA. 

First  Division. 
Loose. 

A.  Single  stones,  more  or  less  accumulated  in 
particular  places,  generally  bearing  marks  of  waste 
in  a  greater  or  less  degree,  and  commonly  consist- 
ing of  the  older  rocks.     Granite  boulders  are  the 
most  conspicuous  and  frequent :    but  there  are 
boulders  of  other  rocks:    single   in  the  interior  of 
countries,  and  forming  heaps  on  sea  shores. 

B.  Stones  of  various  sizes  mixed  with  sand  or 
clay,  or  both. 


317 

a.  The  produce  of  one  rock:  alluvia  formed  in 

bltU. 

b.  Pebbles  of  flint  with  sand  and  clay.     It  is 
questionable  whether  the  pebbles  were  originally 
rounded,  or  if  they  have  been  worn  by  the  action 
of  water. 

c.  Rounded  fragments  of  various  rocks,  inter- 
mixed with  clay  or  sand.     Alluvia  of  rivers — and 
Diluvian  alluvia. 

d.  Fragments   slightly   rounded,  or  angular, 
with  clay  and  sand.     Alluvia  of  descent. 

C.  Of  fine  materials,  consisting  of  sand  and  clay, 
more  or  less  compacted. 

a.  Clay. 

This  embraces  many  varieties,  containing  differ- 
ent proportions  ofsilex  and  alumine,  and  occasion- 
ally magnesia  and  lime.  The  decomposition  of 
granite  furnishes  an  excellent  porcelain  clay :— • • 
and  gneiss  yields  by  the  same  process  a  white  clay 
of  some  value. 

b.  Clay  with  a  large  proportion  of  sand  :  loam 
of  agriculturalists. 

c.  Compact  sand,  always  with   a  mixture  of 
fine  clay  sufficient  to  consolidate  it :  found  in  the 
alluvia  of  rivers  and  lakes,  and  on  the  sea  shore. 

d.  Clay  containing  inflammable  or  carbonace- 
ous matter  arising  from  the  decomposition  of  ani- 

42 


318 

mals  and  vegetables :  Mud.    Found  in  estuaries, 
and  in  the  deposits  of  sluggish  streams. 

D.  Of  fine  materials,  and  loose  or  incompact. 

a.  Quartz  sand. 

On  sea  shores,  and  also  removed  by  winds,  so 
as  to  form  sand  hills  and  other  similar  inland  de- 
posits, which  are  consolidated  by  the  growth  of 
vegetables.  Long  Island,  New  Jersey,  and  Virgi- 
nia sand  hills. 

b.  Of  calcareous   sand ;     commonly  from  the 
decomposition  of  sea  shells,  and  found  under  simi- 
lar circumstances.    , 

E.  Sand  of  various  constitution,   found  in  partial 
deposits  in  different  places,  and  commonly,  if  not 
always,  arising  from  the  decomposition  oi   rocks, 

a.  Quartz  and  argillite. 

b. felspar. 

Cf  the  sand  of  trap  rocks. 

d.  Mica  :  or  mica  with  clay,  or  felspar,  or 
quartz  or  hornblende,  or  all  of  these.  From  gra- 
nite and  gneiss. 

F.  mixtures  of  various  kinds,  forming  the  soil  of 
agriculturalists.     Some  of  these   are  transported 
materials,  others  are  produced  by  the  decomposi- 
tion of  rocks  in  situ.     Those   arising  from  the  de- 
composition in  situ  of  the  trap  rocks,  of  argillace- 


319 

ous  limestone  and  of  argillite,  are  the  most  fertile 
and  valuable.  ^ 

G.  Vegetable  soil,  or  mould,  consisting  of  a 
mixture  of  any  of  the  preceding  with  a  hydro-car- 
bonaceous compound,  analogous  to  peat,  resulting 
from  the  decomposition  of  vegetables.  This  sub- 
stance confers  fertility  on  the  compound  in  propor- 
tion to  its  quantity,  other  circumstances  being 
equal. 

Second  Division. 
Solid. 
Simple. 

A.  Compacted  sand  of  quartz,  or  recent  sand- 
stones :  sometimes  found  in  the  river  alluvia:  ten- 
der. 

B.  Compacted  shell  sand  :  recent  oolite. 

Frequent  in  the  Bahama  Islands  and  similar  si- 
tuations. The  grains  often  perfectly  round,  and 
serving  to  elucidate  the  origin  of  the  older  lime- 
stones of  this  nature. 

C.  Compact  limestone,  deposited  from  the  wat- 
ers of  existing  rivers  and  lakes  in  large  masses. 

The  travertino  of  Rome,  and  the  stalagmitic 
rocks,  similar  to  that  of  Gibraltar  come  under  this 
head. 

Compound, 


320 

A.  Substances  of  various  kinds  and  sizes  cement- 
ed by  carbonate  of  lime. 

a.  Quartz  sand  cemented  in  this  manner. 
On  sea  shores  and  in  river  alluvia. 

b.  Fragments  of  many  kinds  cemented  in  the 
same  way  into  a  solid  mass. 

On  sea  shores. 

B.  Various  substances  cemented  by  rust  of  iron, 

a.  Quartz,  sand,  and  gravel :  recent  ferrugin- 
ous sand  stone.     Similar   to  the  iron  sand  in  its 
most  solid  state. 

b.  Flint,  gravel,  clay,  and  sand,  cemented  in 
the  same  way. 

Some  trap  rocks  seem  to  undergo  a  similar  pro- 
cess after  disintegration ;  forming  a  recent  tufa. 

SYNOPSIS   OF   THE    OVERLYING   OR  SU- 
PERINCUMBENT ROCKS. 

First  Division. 

Simple  :  or  apparently  so. 

A.  Wacke,  of  the  German  school.  Resembles 
indurated  clay,  with  an  even  and  smooth  earthy, 
or  an  uneven  somewhat  granular  fracture,  and  a 
shining  streak. 

a.  Compact. 

b.  Cellular :  but  generally  in  that  case,  partly 


321 

amygdaloidal,  and  appertaining  to  another  division. 

B.  Indurated  clay :  more  or  less  hard,   with  an 
earthy  and  dull  fracture. 

a.  compact. 

This  is  different  from  the  ferruginous  clays  found 
often  with  the  trap  rocks,  which  pass  into  jasper. 

b.  Cellular. 

Like  var,  A.  b.  it  is  rarely  cellular  in  large  mass- 
es, without  also  containing  amygdaloidal  nodules, 
when  it  passes  to  another  division.  The  colors  of 
this  variety  are  usually  ash,  or  grey,  of  different 
hues,  or  modifications  of  red,  or  brown,  or  pur- 
plish black. 

C.  Claystone.     The  fracture  is  dull  and  earthy, 
and  may  be  smooth  and  even,  or  rough  and  some- 
what  granular,  or   imperfectly  splintery,  or  con- 
choidal.    It  differs  from  the   preceding  substances 
in  hardness;  but  there  are  no  definite  distinctions 
in  this  case.     Its  structure  is  never  schistose,  and 
this,  independently  of  its   geological   differences, 
distinguishes  it  from  argillite. 

a  Massive,  irregular. 

6.  Prismatic,  or  columnar. 

c.  Laminar. 

d.  Cellular. 

The  laminar  structure  is  seldom  seen,  except  on 
the  surface,  and  after  exposure  to  weather.  It  is 


322 

sometimes  combined  with  the  prismatic  structure, 
but  cannot  easily  be  confounded  with  the  schis- 
tose argil  lite.  The  colors  of  clay  stone  are  pale 
greyish,  or  muddy  white,  or  ochre  yellow,  of  vari- 
ous degrees,  or  flesh  color,  or  purplish,  or  differ- 
ent tints  of  grey,  from  smoke  color  to  dark  lead 
grey,  nearly  black. 

This  variety  is  most  common  in  mountain  mass- 
es; it  is  found  but  rarely  in  veins. 

D.  Indurated  clay  stone.  Harder  than  the  for- 
mer, and  distinguished  by  the  superior  lustre  and 
acuteness  of  the  fractures,  which  are  also  granu- 
lar, splintery,  or  conchoidal  It  is  separated,  not 
so  much  on  account  of  its  mineralogical  differ- 
ences, as  from  its  geological  importance.  It  forms 
the  most  extensive  and  the  most  common  rock  of 
this  class  in  the  nonh  of  Great  Britain. 

a.  Massive,  irregular. 

b.  Prismatic,  or  columnar. 

c.  Laminar,    under  the    same  circumstances 
as  C.  c. 

*  The  dark  varieties,  particularly  when  prismatic 
or  in  veins,  are  often  called  basalt,  and  may  be  con- 
sidered as  forming  varieties  under  this  popular 
and  indefinite  term.  It  is  found  in  veins  and  in 
mountain  masses ;  frequently  in  the  former,  and  it 
thus  occurs  sometimes  with  the  seemingly  ancierif 


323 

porphyries  that  traverse  granite.  The  colors  arc 
the  same  as  those  of  the  preceeding  variety.  Some 
specimens  of  brilliant  colors  are  called  jasper,  to 
which  they  approximate. 

E.  Clinkstone.  This  is  still  harder  than  the 
preceeding  variety,  and  is  not  scratched  by  the 
knife  The  fracture  too  is  more  perfectly  splin- 
tery and  conchoidal :  occasionally  somewhat 
granular;  the  lustre  more  considerable,  and  the 
fragments  slightly  translucent  on  the  edges,  it  is 
sonorous,  but  not  more  so  than  many  other  mem- 
bers of  the  trap  family.  Its  mineral  characters 
have  been  mentioned. 

a.  Massive. 

b.  Columnar,  or  prismatic. 

c.  Laminar 

The  dark  varieties  of  b.  have,  like  the  former, 
been  enumerated  among  the  basalts  The  same 
remarks  as  in  the  two  preceeding  cases,  maybe 
made  on  var.  c. 

The  colors  and  geological  positions  are  similar 
also.  The  surface,  when  weathered,  becomes 
arenaceous,  and  has  been  confounded  with  sand- 
stone. 

r\  he  substances  C.  D.  and  E.  pass  insensibly  in- 
to each  other,  as  do  other  rocks. 

F.  Compact  felspar,  including  hornstone.     Its 


324 

superior  hardness,  compactness  and  lustre  distin- 
guish it  from  the  preceeding,  to  which  it  is  allied, 
The  edges  are  more  decidedly  translucent. 
a.  Imperfectly  laminar. 

6.  Massive,  with  a  smooth,  splintery,  and  con- 
choid al  fracture. 

c.  Crystalline-granular. 

The  var.  a.  and  b.  occur  simple,  in  veins,  but  are 
frequently  slightly  porphyritic  in  some  places: 
never  as  mountain  masses. 

Var.  c.  assumes  different  aspects  according  to 
its  fineness.  The  colors  are  usually  those  of  the 
preceding  varieties :  but  sometimes,  grains  of  two 
colors  (as  white  and  dark  lead- blue,  or  greyish 
green  and  blackish  green)  occur,  and  it  has  then 
been  mistaken  for  greenstone. 

Fawn  and  cinnamon  colors  are  seen  in  var.  "a. 
b.  also  brick  red,  muddy  white,  and  of  every  tint 
from  grey  to  black.  From  clinkstone  to  compact 
felspar,  there  seems  to  be  a  gradation  similar  to 
that  between  C.  D.  E.  Simple  compact  felspar 
passes  very  generally  into  porphyry.  The  varie- 
ties C.  D  E  F.  in  the  same  way,  become  por- 
phyritic or  amygdaloidal. 

The  preceding  rocks,  particularly  C.  D,  E.  lose 
their  natural  characters  for  some  depth  beneath 
the  surface;  retaining  their  solidity,  but  acquiring 


325 

an  arenaceous  aspect,  and  changing  color,  so  that 
the  dark  indurated  claystone  or  clinkstone  as- 
sumes the*  appearance  of  indurated  clay,  var.  B. 

G.  Hornblende  compacted  into  a  solid  mass, 
and  apparently  consisting  of  minute  crystalline  par- 
ticles. The  fracture  is  coarse  grained,  and  is,  fur- 
ther, uneven,  splintery,  or  conchoidal.  It  varies  in 
lustre — sometimes  glistening.  It  is  one  variety  of 
basalt :  the  only  basalt  of  some  authors. 

Basalt  by  analysis,  yields  soda,  but  hornblende 
does  not. 

a.  Massive,  irregular. 

b.  Laminar. 

c.  Columnar  or  prismatic. 

This  basalt  is  found  in  veins  and  masses — in  the 
former,  laminar.  The  var.  b.  c.  are  sometimes 
joined,  as  in  clay  stones,  the  laminae  being  either 
parallel  or  at  right  angles  to  the  axis  of  the  prism. 

Basaltic  columns  are  sometimes  jointed,  as  be- 
fore mentioned :  but  that  structure  is  not  confined  to 
basalt ;  nor  is  it  characteristic. 

Second  Division. 

Compound  :  formed  of  two  substances. 
Granitiform  mixtures. 

A.  Hornblende  and  compact  felspar. 
a.  In  nearly  equal  proportions,  or  the  horn- 
43 


blende  predominant,  and  the  two  minerals  distinct- 
ly visible.     Greenstone. 

It  occurs  in  veins  and  in  mountain  masses ;  and 
like  some  of  the  preceding  is  columnar,  as  well  as 
laminar.  The  hornblende  is  black  or  dark  green 
and  sometimes  crystallised.  The  felspar  is  white, 
yellowish,  red  of  different  hues,  pale  green,  or  grey 
from  light  to  nearly  black.  The  relative  propor- 
tion, and  size,  and  color,  of  the  particles  give  a 
variety  of  aspects.  Rocks  not  distinguishable  from 
the  dark  varieties  occur,  togetner  with  granite,  as 
already  mentioned. 

The  felspar  is  sometimes  accumulated  in  spots, 
in  the  mixture,  presenting  a  porphyritic  aspect, 
and  forming  pseudo-porphyries. 

When  the  felspar  is  red,  the  compound  is  oft- 
en mistaken  for  granite. 

b.  Compact  felspar  predominant.  Syenite. 
It  occurs  mostly  in  mountain  masses,  rarely  in 
veins.  It  is  occasionally  partially  laminar,  and 
columnar.  Like  other  members  of  this  family,  it 
does  not  preserve  the  same  appearance  for  any  con- 
siderable extent— varying  with  the  proportions  of 
the  constituents  It  is  sometimes  even  simple,  to 
the  exclusion  of  hornblende.  This  is  one  of  the 
Syenites,  of  this  fenady. 


327 

c.  The  mixture  imperceptible,  or  nearly  so; 
to  the  naked  eye.  In  this  variety  the  hornblende 
is  in  equal  or  greater  proportion  than  the  felspar, 
which  is  usually  dark ;  hence  the  compound  is 
dark  grey,  or  greenish  black  or  nearly  black. 
This  is  sometimes  called  basalt :  presenting  the 
same  appearances  as  some  varieties  of  D.  E.  and 
G.  First  division — and  like  them  columnar  as  well 
as  laminar  occasionally. 
B.  Hornblende  and  common  felspar. 

a.  In  nearly  equal  proportions. 
The  rocks  of  this  variety  are  generally  called 
greenstone,  although  differing  in  appearance  from 
the  varieties  of  A.  into  which,  however,  they  pass. 
Some  mineralogists  call  them  syenites;  they  do 
pass  into  them  by  an  increase  of  felspar.  When 
the  felspar  is  red,  they  resemble  some  varieties  of 
granite. 

6.  The  felspar  predominant. 
This  too  forma  one  of  the  prevailing  varieties  of 
Syenite :  and   is  found   under  precisely  the  same 
circumstances  as  var  A.  b.     Its  aspects  is  more  de- 
cidedly granitic   than  the  variety  containing  com- 
pact felspar.     When  the  felspar  is  dark  gray,  as  is 
sometimes  the  case,  the  compound  has  been  im- 
properly termed  greenstone. 
C.  Compact  felspar  and  quart" 


328 

This  occurs  occasionally  in  conj  action  with  syen- 
ite and  the  simple  rocks.  Quartz  is  found  in  the 
same  way  connected  with  indurated  clay  andclink- 
stone. 

D.  Common  felspar  and  quartz. 

This  compound  occurs  among  syenites  and  ana- 
logous rocks. 

E.  Hornblende  and  glassy  felspar. 

This  is  rare,  and  occupies  but  small  spaces, 

F.  Augit  and  compact  felspar. 

a.  The  augit  in  equal  or  superior  proportion 
to  the  felspar,  distinctly  intermixed.     Augit  rock. 

This  occurs  in  veins  and  extensive  masses ;  and 
is  occasionally  laminar  and  columnar.  Its  appear- 
ance varies  according  to  the  relative  proportion, 
size,  and  color  of  the  augit. 

b.  In  such    a  state  of  intermixture    that  the 
parts  are  nearly  or  altogether  invisible. 

The  colors  of  this  compound  are  black,  or  with 
some  shade  of  green.  It  has  been  confounded 
with  some  basalts—having  the  same  fracture  gen- 
eral appearance. 

c.  The  felspar  in  excess,  and  both  minerals 
distinct. 

This  compound  resembles  the  analogous  varie- 
ties of  syenite,  into  which  hornblende  enters.  Like 
the  common  varieties  of  Syenite,  it  presents  vari- 
ous aspects. 


329 

(jr.  Augit  with  glassy  felspar. 

Perhaps  augit  forms  other  compounds  :  it  occa- 
sionally is  an  ingredient  in  a  ternary  compound 
with  hornblende, 

H.  Hjperstene  with  compact  felspar. 

I. common  felspar. 

K. glassy  felspar,  and  some- 
times with  the  addition  of  common  felspar.  Hyper- 
stene  rock. 

These  three  varieties  have  been  insisted  on  by 
Dr.  Macculloch.  They  occur  in  beds,  in  moun- 
tain masses :  never  in  veins,  nor  columnar.  Oc- 
casionally they  exfoliate  like  granite,  and  some- 
times possess  a  foliated  structure  like  gneiss, 
from  the  parallel  position  of  the  hyperstene.  The 
structure  is  generally  granitic,  and  varies  accord- 
ing to  the  size  and  proportion  of  the  ingredients. 
Sometimes  it  resembles  granite,  and  at  others 
greenstone:  and  with  an  addition  of  imbedded 
crystals  of  felspar,  it  occasionally  resembles  grap- 
hic granite,  W  hen  very  fine,  it  approaches  to  ba- 
salt. 

Compound :  of  two  substances  ;  one  of  which  is  more 
or  less  distinctly  crystallised  and  embedded  in  a  simple 
base  of  the  other.  Includes  some  porphyries. 


330 

A.  Claystone,  common  or  indurated,  with  imbed- 
ded scales   of  mica,  sometimes   regularly  crystal- 
lised. 

This  is  found  in  veins  and  in  masses ;  but  is 
rare. 

B.  Grains,  or  imperfect  crystals  of  quartz  im- 
bedded in  a  simple  base. 

a.  Base  of  claystone. 

b.  — •  indurated  claystone, 

c. clinkstone. 

<£ compact  felspar. 

The  colors  vary  with  that  of  the  base.  They 
usually  are  found  together  with  the  simple  rocks 
forming  the  bases. 

C.  Crystals   of  felspar  imbedded  in  a  simple, 
or  apparently  simple  base.     Porphyry. 

Bases  a.  b.  c.  d.  as  the  preceding. 

These  are  the  most  common  simple  porphyries. 
The  crystals  may  be  common  or  glassy  felspar,  or 
both.  The  felspar  is  sometimes  opake  and  dull, 
as  if  beginning  to  decompose;  at  other  times  it  is 
powdery.  And  again  the  place  may  be  partially 
filled  with  an  ochry  powder,  the  mass  appearing 
carious. 

The  colors  of  course  are  liable  to  all  the  vari- 
eties of  the  simple  rocks  forming  the  bases;  other 


331 

varieties  arise  from  the  color  of  the  crystals,  or 
their  mode  of  disposition.  The  cross  crystals  are 
the  most  remarkable.  By  the  gradual  exclusion 
of  the  crystals,  the  porphyries  pass  into  simple 
rocks.  They  occur  in  veins  and  in  mountain 
masses. 

The  var.  a.  b.  c.  are  found  mostly  among  the 
later  secondary  rocks,  but  occasionally  even  with 
granite,  like  their  bases,  with  var  d.  This  last  is 
most  seen  with  rocks  of  older  date.  They  are  all 
occasionally  laminar,  and  columnar,  like  some 
syenites. 

6.  Base  of  basalt.     Basaltic  porphyry. 

The  basalt  is  of  any  of  those  substances  usual- 
ly called  so — and  the  crystals  frequently  glassy. 

Third  Division. 

Compounds  of  three  or  more  ingredients. 
First  Sub-division. 

Granitiform  mixtures* 

A.  Felspar,  hornblende,  and  quartz      Syenite. 

This  alone  is  the  compound  which  accords  with 
the  common  definition  of  Syenite.  Although  the 
definition  is  upheld,  it  is  constantly  violated  in 
practice. 

The  felspar  may  be  compact  or  common:  the 
former  being  found  among  the  overlying  rocks 


332 

only — and  never,  perhaps,  among  granites,  where- 
as the  latter  compound  is  very  prevalent  with  gra- 
nite, of  which  it  is  a  variety  well  known.  When 
found  with  trap  rocks  the  color  of  the  felspar  is 
often  greenish,  and  the  quartz  being  overlooked, 
the  compound  has  been  termed  greenstone.  The 
aspects  and  colors  of  this  compound,  of  course, 
vary  greatly,  and  depend  upon  the  color,  propor- 
tion and  size  of  the  ingredients. 

B.  Felspar,  hornblende,  and  mica. 

This  is  not  common :  and  has  been  termed  mi- 
caceous greenstone. 

C.  Felspar,  hornblende,  and  chlorite. 
D. and  steatite. 

E.  Felspar,  quartz,  hornblende  and  mica. 
Thevar.  C.  D.  are  rare.     Notwithstanding  the 

similarity  of  var.  E.  to  granite,  its  situation  places 
it  among  these  rocks.  It  appears  to  be  the  com- 
pound that  has  been  called  new  granite. 

It  is  said  that  no  mixture  of  quartz,  mica,  and 
felspar,  has  occurred  among  the  superincumbent 
rocks. 

The  constituents  of  these  syenites  may  be  erys- 
talised,  as  in  granite.  These  varieties  are  some- 
times laminar  as  well  as  columnar. 

F.  Augit,  felspar,  and  mesotype. 


333 

G.  Augit,  felspar,  and  prehnite. 

H.  * calcedony,  or  quartz. 

I. calcedony,  and  prehnite, 

or  mesotype. 

These  are  varieties  of  augit  rock. 

K.  Augit,  felspar,  and  olivin. 

L.  Hornblende,  felspar,  and  epidote. 

These  varieties  are  accidental  or  limited. 

M.  Hornblende,  felspar,  and  prehnite;  some- 
times with  the  addition  of  mica. 

The  prehnite  forms  a  decided  constituent  in  this 
rock. 

N.  Hornblende,  common  felspar,  compact  fel- 
spar, quartz  and  steatite,  and  apparently  augit. 
Found  very  rarely. 

O.  Hornblende,  and  greenish  compact  felspar 
forming  the  chief  part  of  a  mixture  in  which  are 
intermingled  glassy  felspar,  opake  white  felspar, 
augit  in  prisms,  and  mica,  with  pyrites. 

All  these  complicated  varieties  can  be  referred 
to  no  other  than  the  superincumbent  or  overlying 
rocks. 

Second  Sub-Division. 

One  species  of  crystals  imbedded  in  a  compound 
base,  or  two  species  of  crystals  imbedded  in  a  base 
that  is  either  simple  or  compound.  This  includes 

all  the  remaining  porphyries. 
44 


334 

A.  Felspar  crystals  in  a  base  of  greenstone. 
This  is  the  greenstone  porphyry,  exhibiting  dii- 

ierent  aspects  according  to  the  quality  of  the  base 
They  may  be  distinguished  by  a  reference  to  what 
has  been  said  above. 

B.  Felspar  crystals  in  a  base  of  syenite. 

The  same  remarks  apply  to  this  variety,  which 
passes  insensibly  into  porphyritic  granite. 

C.  The  crystals  consisting  of  felspar  and  quartz. 
D. mica. 

E.  . talc. 

F. epidote. 

Q.  „ pinite. 

H. chlorite. 

I. hornblende. 

In  many  of  these  cases,  it  is  difficult  to  ascertain 
if  the  crystals  be  imbedded,  or  if  it  form  part  of 
the  base :  and  in  such  cases  a  gradation  exists  be- 
tween granitiform  and  porphyrtic  mixtures.  Often 
the  cavities  of  porphyries,  like  amygdaloids,  are 
empty. 

Fourth  Division. 

Supra-compounded  rocks. 

This  division  embraces  many  of  those  enumerat- 
ed in  the  preceding  catalogue  as  bases,  in  which 
nodules  of  several  adventitious  minerals  are  im- 
bedded. Amygdaloids. 


Indurated  clay  B.  div.  1st  different  varieties,  is 
the  most  frequent  base. 

The  porphyritic  and  amygdaloidal  structures 
may  be  combined,  and  thus  produce  many  incident- 
al varieties.  The  amygdaloids  may  contain  one  or 
more  minerals,  giving  rise  to  several  varieties. 

The  size  of  the  nodules,  and  their  quantity  di- 
versify the  aspect.  The  nodules  do  not  always 
fill  the  cavity  that  contains  them.  Two  or  more  mi- 
nerals sometimes  occur  in  the  same  cavity,  as  agate 
and  calcareous  spar.  The  amygdaloid  may  have 
large  portions  containing  empty  cavities,  others 
partially  and  others  wholly  filled — resembling 
sometimes  cellular  or  scoriform  lavas. 

The  transition  is  often  imperceptible  from  simple 
rocks  to  amygdaloids. 

From  these  circumstances  the  variety  of  amygd- 
aloids is  great :  those   containing  the  calcareous 
spar  and  the  zeolites  are  the  most  abundant.     The 
nature  of  the  imbedded  mineral,  the  characters  of 
the  bases,  and  the  many  combinations  give  rise  to 
too  many  modifications  to  enumerate  them  all. 
The  list  of  minerals  contains  those  usually  found, 
and  in  the  order  of  their  relative  frequency  :  viz. 
Siliceous  Minerals. 
Calcedony  :  rariously  colored,  ^oned,  and  striped : 


Cacbolopg;  and  semi  opal 


336 

Hyalite, 
Heliotrope. 

Brown  carnelian  :  calcedony  colofed  by  chlorite 
Chert. 

Qjuarz,  with  different  degrees  of  opacity. 
Amethyst. 

Zeolitic  Minerals. 

Mesotype  Prelmite 

Nadelstein  Laumonite 

Analcime  Ichthyophthalm* 

Stilbite  Harmotome. 
Chabasie 

Calcareous  Minerals, 

Carb.  of  lime  Flour  spar 

Brown  spar  Arragonite. 

Schiefer  spar. 

Miscellaneous  Minerals. 

Sulphat  of  barytes  Steatite 

Sulphatof  Strontian  Lithomarge 

Olivin  Chlorophoeite 

Epidote  Conite 

Mica  Leucite* 
Chlorite. 

Metallic  Minerals. 

Specular  iron  Copper 

Pyrites  Galena. 

The  following  minerals  sometimes  occur  in  the 
preceding  rocks :  and  may  be  considered  as  adven- 
titious. 

Apatite  Garnet 

Tourmaline  Opal 

Abestos  Meionite 

Schiller  spar  Sommite. 

The  two  last  perhaps   belong  rather  to  lavas 

than  traps.     They  have  all  been  found  in  recent 
greenstones  and  basalts; 


337    , 

Precious  epal  and  chrysoprase  occur  occasion- 
ally in  certain  porphyries. 

The  amygdaloids  generally  occur  in  large 
masses:  rarely  in  veins.  In  both  cases,  they  are 
occasionally  laminar. 

Fifth  Division. 

Conglomerates. 

The  substance  included  under  this  head,  is  also 
mentioned  under  Conglomerate  rocks. 

A.  Fragments  of  different  trap  rocks  and  of 
various  sizes,  angular,  and  re-united  into  a  solid 
mass.  Trap  tuff! 

a.  Fine,  tuffaceous. 

b.  Conglomerated  ;  coarse.    Trap  conglome- 
rates. 

1  hey  form  beds  or  masses  intermixed  with  the 
other  varieties.  Sometimes  they  contain  portions 
of  carbonised  wood,  or  of  foreign  rocks — and  may 
then  be  called  transported  conglomerates. 

SYNOPSIS  OF  VOLCANIC  ROCKS. 

Preliminary  remarks. 

Geologists  are  much  divided  as  to  the  substan- 
ces that  strictly  come  under  this  head.  Where  vol- 
canoes have  been  long  extinct,  and  some  of  the  most 
decisive  characters  have  been  lost,  much  dispute 


338 

has  arisen  as  to  the  substances  that  formed  part 
of  the  mountain  previous  to  the  existence  of  the 
volcano,  and  as  to  those  acknowledged  to  have 
been  the  produce  of  it.  The  chief  difficulty  how- 
ever arises  from  the  trap  recks,  which  are  attri- 
buted by  some  to  aqueous  by  others  to  igneous  or- 
igin ;  and  many  of  which  so  closely  resemble  vol- 
canic products,  that  they  are  thought  to  be  of  simi- 
lar origin. 

The  structure  is  the  same  as  that  of  the  trap 
family  :  viz,  the  prismatic,  and  lamellar,  as  well 
as  the  cavernous,  amygdaloidal  and  porphy- 
ritic. 

Respecting  the  imbedded  minerals,  much  dis- 
pute has  arisen  as  to  whether  they  are  ejected 
unaltered,  whether  they  are  formed  in  the  lava  by 
chemical  affinities,  or  whether  they  are  not  pro- 
duced by  infiltration. 

..;-,/' 

First  Division. 
More  or  less  perfectly  vitreous. 

First  Sub-division. 
Solid. 
A.  Obsidian :  volcanic  glass. 

a.  Massive. 

b.  With  an  imperfect  laminar  structure. 

c.  Concretionary  ;  imperfectly  spheroidal  OF 
granular. 


339 

rf.  Fibrous,  loose — rare. 
c.  Porphyritic;  inclosing  felspar.    Obsidian- 
porphyry, 

Black,  dark  green,  pale  muddy  green,  grey  and 
brown  are  the  usual  colours.  It  is  sometimes  stri- 
ped. The  lustre  and  opacity  vary.  In  one  in- 
stance it  has  been  found  to  contain  mica. 

Second  Sub-division. 
Cavernous. 

A.  Cavernous  Obsidian;  passes  to  pumice. 

B.  Pumice. 

a.  Simply  cellular. 

b.  Cellular  protracted,  becoming  nearly  fi- 
brous. 

C.  Scoria.     Formed  of  a  less  perfect  glass,  and 
passing  to  porous  lava. 

Second  division. 

With  a  base  of  compact  felspar  j  or  supposed  to 
be  so. 

A.  Simple ;  solid,  or  imperfectly  granular. 

B.  Porphyritic  :  pale  volcanic    porphries. 
The  pale  lavas  belong  to  this  division.    Felspar 

is  not  necessarily  the  only  imbedded  mineral. 

Third  Division. 

With  a  base  of  basalt,  or  some  analogous  sub- 
stance, simple  to  the  eye. 


*• 

340 

A.  Simple  :  dark  lava,  and  scoriform  lava, 

a.  Compact :  compact  lava. 

b.  Porous :  cavernous  lava,  or  scoria ;    The 
caverns  are  often    partially  filled  with    substances 
entering  into  volcanic  amygdaloid^,  into  which  this 
passes. 

c.  Prismatic,  or  columnar :  volcanic  basalt  of 
writers. 

d.  Concretionary  on  a  smaller  scale :  spheroi- 
dal or  otherwise, 

B.  Compound  :  containing  felspar  :    porpyries ; 
other  minerals  beside    felspar  may  be  imbedded. 

C.  Compound  :     containing  amygdaloidal   no- 
dules :  Volcanic  amygdaloid. 

The  imbedded  nodules  are  usually  calcareous 
or  fluor  spar,  zeolitic  minerals  and  calcedony. 
As  they  are  sometimes  accompanied  by  water,  they 
seem  to  have  been  produced  by  infiltration.  The 
colors  afe  black,  brown,  grey,  &c.  depending 
often  on  the  number  and  nature  of  the  imbedded 
minerals.  A  list  of  imbedded  substances  will  be 
seen  presently. 

Fourth  Division. 

With  a  base  of  greenstone,  or  some  analogous 
compound.  Augit  seems  to  have  usurped  the 
place  of  hornblende. 

A.  Simple. 


341 

B.  Porphyritic. 

C.  Amygdaloidal. 

This  division  contains  similar  varieties  with  the 
last. 

Fifth  Division. 

With  a  base  of  common  felspar. 

These  are  granitic  compounds,  but  distinct  from 
ejected  granite.  All  these  lavas  present  various 
modifications  of  external  form,  arising  from  the 
manner  in  which  these  have  flowed,  and  similar  to 
those  found  in  the  slags  of  furnaces.  ' 

Sixth  Division. 

Ejected  substances,  more  or  less  altered  by  the 
fire. 

First  Sub-division. 
Solid :  conglomerates. 

A.  Conglomerates  of  various  fragments  of  differ- 
ent rocks,  with  mica,  augit,  and   other  minerals. 

B.  Conglomerates  consisting  chiefly  of  clay,  and 
having  apparently,   been  ejected  in  the  state  of 
mud.    Tufa. 

a.  Coarse  tufaceous  conglomerates. 

b.  Fine  and  powdered  tufa. 

These  latter  varieties  often  containing  augit., 
mica,  and  other  imbedded  minerals,  as  well  as  the 

solid  lavas. 

45 


342 

Second  Sub-division . 
Loose. 

A.  Fragments  of  various  rocks,   both  primary 
and   secondary,  more  or  less  altered  by  the  fire. 

B.  Powdery,  puzzolana,  dust,  ashes. 

The  following  are  the  chief  imbedded  miner- 
als found  in  these  rocks.  The  amygdaloidal 
minerals  are  not  added. 

Felspar  Melanite 

Pyroxene  Idocrase 

Garnet  Toumaline 

Hornblende  Apatite 

Peridot  Zircon 

Mica  Ice  spar 

Hauyne  Pleonaste 

Meioniete  Arragonite 

Melilite  Sphene 

Tabularspar  Oxydulous  iron 

Sommite  Copper 

Leucite  Selenium 

SYNOPSIS  OF  CONGLOMERATE  ROCKS. 

Preliminary  remarks* 

Many  of  the  rocks  noted  under  this  head,  have 
already  been  mentioned — but  for  sake  of  more 
easy  reference  are  again  introduced  among  the 
more  important  varieties. 

These  rocks  occur  among  the  primary  and 
secondary  strata,  and  are  sometimes  very  limited, 
at  others  occupying  extensive  tracts.  They  may 
be  divided  into  general  and  local. 


343 

The  former  constitute  portions  of  those  mixed 
rocks,  whose  origin  is  mechanical,  and  are  formed 
of  large  fragments  of  the  same  substances,  which* 
when  in  more  minute  division  compose  the  finer 
strata.  They  must  of  course  contain  both  simple 
and  compound  rocks  of  older  origin  than  them- 
selves— as  for  example,  the  red  sand-stones  and  ar- 
gillites.  The  materials  are  united  without  any 
distinct  cement  of  a  crystalline  nature,  particu- 
larly in  the  secondary  class :  and  the  fragments 
are  more  or  less  rounded.  In  some  instances  they 
seem  to  be  only  portions  of  the  finer  rocks  which 
they  accompany,  in  others  they  form  extensive 
strata. 

Local  conglomerates  are  generally  confined  to 
the  superficies  of  some  simple  rock — and  are 
most  various  in  lime-stones.  Their  composition 
is  regulated  by  that  of  the  adjoining  rock.  When 
between  different  rocks  they  contain  fragments  of 
both  generally  angular.  These  remain  where  their 
parts  were  united  but,  in  general  conglomerates 
the  constituents  have  undergone  transportation. 
The  one  arising  from  simple  fracture  and  re-union 
— ihe  other  originating  from  important  and  exten- 
sive revolutions — and  may  be  called  the  consoli- 
dated alluvia  of  former  ages. 


344 

The  minerals  entering  into  the  local  conglome- 
rates are  few,  and  are  most  frequently  united  by 
distinct  cement — of  fine  materials,  or  of  crystalline 
matter,  particularly  among  calcareous  conglome- 
rates. 

Trap  conglomerates  are  local,  and  are  formed  by 
operations  peculiar  to  those  rocks — sometimes 
containing  bituminous  wood  and  fossil  remains. 

First  Division. 

Consisting  of  fragments  of  one  rock,  either  im- 
bedded in  a  continuous  base  of  the  same  sub- 
stance, or  re-united  chiefly  by  minuter  fragments, 
or  united  by  veins  of  carbonate  of  lime,  or  of 
quartz. 

A.  Consisting  of  limestone  alone  :  local. 

a.  With  angular  fragments. 

This  occurs  among  primary  and  secondary  rocks 
— and  includes  the  ornamental  breccia-marbles. 
It  is  local,  confined  to  some  simple  limestone.  The 
union  is  effected  by  carbonate  of  lime. 

b.  With  rounded  fragments. 

The  materials,  which  may  be  primary  or  secon- 
dary, have  been  transported.  It  does  not  occur 
in  large  strata  or  masses — nor  attached  to  any 
particular  rock?  as  the  preceeding. 


345 

B.  Consisting  of  fragments  of  quartz,  or  quartz 
rock  alone  united  in  various  ways. 

a.  With  angular  fragments. 

Local — connected  with  quartz- rock— of  course 
primary. 

b.  With  rounded,    or  angular  and   rounded 
fragments  together. 

One  of  the  varieties  of  quartz- rock,  under  which 
head  it  is  mentioned. 

C.  Consisting  of  fragments  of  jasper,  united  by 
quartz  or  calcedony : — agate — local. 

D.  Consisting  of  fragments  of  gneiss,  of  various 
sizes,  agglutinated. 

This  variety  is  local — attached  to  gneiss — and 
forms  the  first  bed  of  primary  sandstone,  where 
that  rock  rests  on  gneiss :  it  is  necessarily  primary. 

E.  Consisting  of  fragments  of  argillite,  re-united 
by  smaller  particles  or  by  clay — or  imbedded  in  a 
continuous  schist. 

It  is  primary  and  local — and  noticed  under  the 
head  of  Argillite.  It  may  occur  as  secondary,  and 
transported. 

F.  Consisting  of  chlorite  schist  formed  similar- 
ly to  E  :  local. 

Accompanies  chlorite  schist,  and  is  primary. 

G.  Fragments  of  the  different  trap  rocks  re-unit- 
ed by  finer  particles  of  the  same. 


346 

a.  With  angular  fragments. 

Trap  tuff,  mentioned  among  the  overlying  rocks  . 
local. 

b.  With  rounded  and  angular  fragments  both- 
The  materials  are  transported — but  this  is  con- 
fined to   the  vicinity  of  trap  rocks — and  often   of 
partial  occurrence.      May  be  either  primary  or 
secondary. 

Similar  Conglomerates  may  occur,  consisting  of 
the  fragments  oi  mica  schist. 

Second  Division. 

Consisting  of  two   rocks  or  substances,  united 
similarly  to  the  varieties  of  the  former  division. 

A.  Serpentine  and    limestone ;     or  calcareous 
spar  :  local.     It  generally  occurs  between    lime- 
stone and  serpentine — and  is  necessarily  primary 
— it  includes  the  verde  antique. 

B.  Fragment,  of  argillite  with  limestone. 

a.  Argiilite  imbedded  in  limestone. 

b.  A  confused  mass  of  fragments  of  both. 

c.  Fragments  of  limestone  imbedded  in  argil- 
lite. 

These  are  primary — and  some  of  them  valuable. 

C.  Fragments  of  limestone   imbedded  in  mica 
schist :  local. 

D.  Fragments  of  granite  with  mica  schist  or 
gneiss  :  local. 


347 

a.  The  fragments  of  granite  imbedded. 

b.  Confused  mass  of  fragments  of  granite,  and 
of  mica  schist,  or  gneiss. 

E.  Granite  uniting  fragments  of  the  same  rocks 
and  offering  similar  modifications. 

Where  mica,  schist  or  gneiss  approximates  to 
granite  the  latter  often  contains  so  many  fragments 
of  those  rocks  as  to  seem  conglomerate. 

F.  Quartz  imbedded  in  limestone :  local. 

a.  In  angular  fragments. 

b.  In  rounded  pebbles. 

These  are  both  primary  and  secondary. 

G.  Trap  imbedded  in  limestone,  and  in  the  acr 
companying  shale  :  local. 

The  trap  is  usually  in  rounded  nodules — and  ap- 
parently weathered :  occurs  in  secondary  limestone. 

H.  An  aggregate  of  fragments  of  argillite  and 
chlorite  schist :  local. 

This  occurs  where  the  two  rocks  accompany 
each  other,  and  is  local. 

I.  Sandstone  with  quartz. 

a,  The  quartz  in  angular  fragments. 

b.  The  quartz  in  rounded  nodules,  or  united 
with  angular  fragments. 

II.  Sandstone  and  lime  united. 

«.  Fragments  of  sandstone  imbedded  in  lime- 
atone. 


6.  Fragments  of  limestone  imbedded  in  sand- 
stone. 

c.  An  aggregate  of  the  fragments  of  both. 

These  are  general  and  belong  to  the  secondary 
sandstones — mostly  to  the  lowest. 

They  are  mentioned  under  the  heads  of  the  dif- 
ferent rocks  to  which  they  belong. 

L.  Sandstone  and  argillite,  or  shale,  united  : 
general.  The  sandstone  usually  forms  the  base  • 
is  enumerated  under  that  head. 

Third  Division. 

Consisting  of  three  or  more  rocks,  o  substances 
united. 

These  are  the  most  common :  they  consist  of  frag- 
ments, rounded  or  angular,  or  both,  united  by 
means  of  clay,  sand,  and  gravel,  derived  from  the 
same  substances. 

A  Fragments  of  quartz,  and  of  a  greater  or  less 
number  of  primary  rocks,  united. 

In  various  states,  this  forms  conglomerates  at- 
tached to  sandstones,  under  which  head  it  is  men* 
tioned.  It  maybe  primary  or  secondary,  the  former 
containing  the  more  limited  number  of  ingredients. 

B.  Fragments  of  primary  rocks  with  limestones. 

C.  Fragments  of  the  same  rocks  with  trap. 


349 

This  is  similar  to  A.  and  is  found  in  connection 
with  trap. 

D.  Fragments  of  granite,  limestone,  quartz  and 
gneiss  imbedded  in  mica  schist. 

This  is  found  where  limestone  accompanies  mi- 
ca schist — or  where  the  latter  rock  and  gneiss  ap- 
proximate to  granite. 

E.  Fragments  of  several  primary  or  secondary 
rocks,  or  both,  with  fragments  of  trap. 

This  is  a  trap  tuff,  and  noticed  with  the  overly- 
ing rocks.  It  is  in  this  and  a  few  similar  varieties 
of  the  most  recent  origin  that  organic  remains  have 
occasionally  been  found. 

Some  of  the  finer  varieties  of  these  rocks  are 
noticed  under  the  head  of  argillite,  being  frequent- 
ly termed  grey  wacks. 


46 


TABULAR  ARRANGEMENT 

OF 

FORMATIONS, 

Observed  in  both  Hemispheres  (1822) 

BY 

BARON  HUMBOLDT. 

Roman  numerals  are  perfixed  to  the  names  of 
those  formations,  which  being  very  seldom  want- 
ing, and  consequently  extending  most  generally, 
may  be  considered  as  geognostic  horizons. 

Primitive  Formations. 
\.  Primitive  granite. 

Primitive  granite  and  gneiss. 
Stanniferous  granite. 
Weistein  with  serpentine. 
II.  Primitive  gneiss. 

Gneiss  and  mica-slate. 

Granite  posterior  to  gneiss,   anterior  to  mica- 
slate. 

Primitive  sienite  ? 
Primitive  serpentine  ? 
Primitive  limestone. 

The  five  latter  formations,  placed  between  gneiss 
and  primitive  mica- slate,  are  parallel  formations. 


351 

III.  Primitive  mica-slate. 

Granite  posterior  to    mica-slate,  anterior  to 

clay  slate. 

Gneiss  posterior  to  mica-slate. 
Greenstone  slate  ? 

IV.  Primitive  clay  slate. 
Quartz  rock. 

Granite  and  gneiss  posterior  to  clay  slate. 
Primitive  Porphyry. 

V.  Primitive  euphotide,  posterior  to  clay  slate. 
The  four  latter  formations,  are  parallel  to  each 
other,  sometimes  even  to  primitive  clay  slate. 

Transition  Formations. 
I.  Granular  talcose   limestone,  transition  mica 

slate,  and  grauwacke  with  anthracite. 
II.  Transition  porphyries  and  sienites,  immedi- 
ately covering  primitive  rocks ;  black  lime- 
stone and  greenstone. 

HI.  Transition  clay  slate,  containing  grauwacke, 
greenstone,  black  limestone,  sienite  and 
porphyry. 

IV.  &  V.  Porphyries,  sienites,  and  greenstonepos- 
terior  to  transition  clay-slate,   some  times 
even  to  limestone  with  orlhoceratites. 
VI.  Transition  euphotide. 


352 

Secondary  Formations. 

I.  Great  coal  deposit,  red  sand  stone,  and  secon- 

dary porphyry  (with  interposed  amygdaloid  r 
greenstone  and  limestone.) 
Secondary  quartz  rock, 

The  latter   formation  is   parallel   to  coal-sand- 
stone. 

II.  Zechstein  or    alpine    limestone  (magnesian 

limestone  ) :    hydrated  gypsum ;  rock  salt. 
The  five  following  formations  which  are  very  un- 
equally developed    may  be  comprehended 
under  the  general  name  of 

III.  Arenaceous  and  calcareous  deposits  (marly 
and  oolitic,  placed  between  the  zechstein 
and  the  chalk,  and  connected  with  these 
two  formations.) 

Clay  and  variegated  sandstone  (sandstone 
with  oolite  :  sandstone  of  Nebra;  new  red 
sandstone  and  new  red  marl)  with  gypsum 
and  rock  salt. 

Muschelkalk  (shell,  limestone;  of  Gottinguen.) 
Quardersandstein  (sandstone  of  Konigstein.) 
Jura  limestone  (lias,  marie,  and  great  oolitic, 

deposits. 

Ferruginous  sand  and  sandstone,  secondary 
sandstone  with  lignite  (iron  sand  and  green- 
sand.) 


IV.  Chalk. 

Tertiary  Formations. 

I.  Clay  and  tertiary  sandstone  with  lignite  (plas- 
tic clay,  molasse,  and  nagelfluhe  of  Argovia.) 

II.  Limestone  of  Paris  fcalcaire  grossier,  or  lime- 

stone with  cerithia,  a  formation  parallel 
to  the  London  clay,  and  to  the  arenaceous 
limestone  of  Bognor.) 

III.  Siliceous  limestone,  gypsum  with  bones,   al- 

ternating   with   marl    (gypsum  of  Mont- 
matre.) 
IV.  Sandstone,  and  sand  above  the  gypsum  with 

bones — (sandstone  of  Fontainebleau.) 
V.  Fresh -water  formation  with  porous  millstones 
(meuliere  above  the  sandstone  of  Fontaine- 
bleau (limestone  with  (lymneae.) 

Formations  (exclusively}  volcanic. 
I.  Trachytic  formations. 

Granitoid  and  sienitic  trachytes. 

Porphyritic  trachytes  (feldspathic  and  pyrox- 
enic.) 

Phonolites  of  trachytes  (simi-vitreous  trachy- 
tes.) 

Pearlstone  with  obsidian. 

Millstone  and  cellular  trachytes,  with  silice- 
ous nodules. 


354 

Trachytic  and  pumce  conglomerates,  with 
alumstone,   sulphur,     opal,   and    opalised 
wood. 
II.  Basaltic  formations. 

Basalt  with  olivin,  pyroxene,  and  a  little  horn- 
blende. 

Phonolite  of  basalt. 

Dolerite, 

Cellular  Mandelstein. 

Clay  with  p)  rope-garnets. 
This  small  formation    seems  to   be   connected 
with  the  clay  with  lignite  of  the  tertiary  formation, 
over  which  currents  of  basalt  are  often  spread. 

Conglomerates  with  basaltic  scoria?. 

III.  Lavas  that  have  issued  from  a  volcanic  crater 
(ancient  lavas,  vast  masses  generally  abound- 
ing in   felspar;    modern  lavas   with  distinct 
currents  of  small  breadth  ;  obsidian  with  la- 
va and  pumice  of  obsidian.) 

IV.  Volcanic  tufa,  with  shells. 

Deposits  of  compact  limestone,  marl,  clay  with 
lignite, gypsum  and  oolite,  super  posed  on  the  most 
modern  volcanic  tufas.  These  small  local  forma- 
tions belong  perhaps  to  the  tertiary  rocks  :  Table- 
land of  Rio  bambo :  isles  of  Fortaventura  and 
Lancerote. 


ARRANGEMENT  OF  ROCKS, 

On  the  principles  of  Werner,  by  his  pupil  Pro- 
fessor Jameson,  of  Edinburgh,  and  which  may  be 
considered  as  "  Werner's  own" — as  it  is  probable 
that '  the  celebrated  Geognost  would  have  made 
similar  modifications  in  his  original  arrangement. 
CLASS  I.  Primitive  Rocks. 

1.  Granite,  with    Sienite     6.  Primitive  trap. 

and  Topaz  rock.         7.  Serpentine. 

2.  Gneiss,    with   White-     8.  Euphotide,  or  Dial- 

stone,  lage  rock. 

3.  Mica  slate.  9.  Porphyry. 

4.  Clayslate  (Argillite.)       10.  Quartz  rock. 

5.  Primitive  limestone, 

and  Gypsum. 

Cuss  If.   Transition  Rocks. 

1.  Greywacke,  including     5.  Serpentine. 

transition  Clay  slale     6.  Quartz  rock. 

2.  Limestone.  7.  Red  sandstone. 

3.  Granite,  and  Porphyry    8.  Trap. 

4.  Gneiss,  and  Mica  Slate.  9    Gypsum. 

CLASS  III    Secondary  Rocks. 

1.  Sandstone,  including       3.  Gypsum,    including 

the  coal  formation.  Salt. 

2.  Limestone,  including      4.  Trap,   including  se- 

Chalk.  condary  Sieuite. 

CLASS  IV.  diluvial  Deposits. 
CLASS  V.   Volcanic  Rocks* 


TABULAR  VIEW, 

BY 

DR.  MACCULLOCH. 

I.  PRIMARY  CLASS. 

Unstratified. 

Granite. 

Stratified. 

Gneiss  Red  Sandstone. 

Micaceous  Schist  Argillaceous  Schist 

Chlorite  Schist.  Diallage  Rock. 

Talcose  Schist.  Limestone. 

Hornblende  Schist.  Serpentine. 

Actynolite  Schist.  Compact  Felspar, 

Quartz  Rock. 

II.  SECONDARY  CLASS. 

Stratified. 

Lowest  (red)  Sandstone.  Limestone. 
Superior  Sandstones         Shale. 

Unstratified. 
Overlying  (and  venous)    Pitchstone, 

Rocks. 

Ill  Occasional  Rocks. 

Jasper.  Gypsum. 

Siliceous  Schist.  Conglomerate  Rocks, 

Chert.  Veinstones. 

APPENDIX. 

Volcanic  Rocks.  Alluvia, 

Clay,  marl,  sand.  Lignite. 

Coal  Peat. 


357 
LIST  OF  FOSSILS  FOUND  IN  THE  UNITED  STATES. 


MEGATHERIUM 

TEREBRATULITE 

MEGALONYX 

ARCA 

MASTODON 

MACTRA 

ELEPHAS 

DONAX 

BOS 

OSTREA 

CERVUS 

GRYPHEA 

BALENA 

PERNA 

MANATUS 

PAT  XL  A 

CONUS 

ICTHYOSAURUS 

CONULARIA 

PLESIOSAURUS 

TEREBELLUM 

SAUROCEPHALUS 

MUREZ 

TESTUDO 

STROMBUS 

TURBO 

SQUALUS 

PLANORBIS 

RAIA 

TURRITELLA  ] 

ACIPENSER  and  many  undeter- 

SERPULA 

mined  genera  and  species* 

BALANUS 

MEDUSA 

GLYCEMERIS 

CANCER 

CYTHEREA 

TRILOBITE 

PRODUCTUS 

ASTERIA 

PENTAMERUS 

ECHINUS 

VENUS 

CARYOPH1LLIA 

CARDIUM 

PENTREMITE. 

CARDITA 

ENCRINITE 

VENERICARDIA 

CUCULL^EA 

AMMONITE 

ANOMIA 

NAUTILITE 

NER1TA 

BELEMNITE 

PECTUNCULUS 

ORTHOCERATITE 

TRIGONIA 

NATICA 

MYTILLUS 

OLIVA 

AMPHIDESMA 

CARDITA 

CORBULA 

BILOBITE 

PANOP(EA 

•  In  a  paper  recently  read  before  the 
Lyceum  of  Natural  History,  Dr.  De- 

CRASSATELLA 
ISOCARDIA 

kay  has  attempted  to  show  that  near- 
ly all  the  fossil  fish  from  the  great  de- 
pository at   Westfield    (Mass.)  and 
which  have  been  referred  to  the  ge- 

CALYPTREA 
LUCINA 
ASTARTE 

nus  Paleothrissum  of  Blainville,  are 

FUSUS 

not  generically  distinct  from  the  Esox 
Osseus,  or  bony  scaled  pike  of  the 
Mississippi 

FULGUR 
DISPOTfEA 

358 


PECTEJN 

HELIX 

PLICATULA 

SERPULA 

CELLAPORA 

MILLEPORA 

ALVEOLITE 

FAVOSITE 

TUBIPORA 

TURBINOLIA 

ASTREA 

MADREPORA 

OCUL1NA 

CORALLIUM 

PENNATULA 


SERTULARIA 

ALCYONITE 

ORBULITE 

BACCULITE 

FASCIOLITE 

DENTALIUM 

AMMONITE 

NUMMULITE 

SPIRULA 

FELICES 
PALMA 
QUERCUS 
JUGLANS  NIGRA 
FAGUS. 


The  following  fossils  have  heen  enumerated  by  Dr.  Bigs  by 
in  his  geological  papers  on  the  country  around  Lakes  Huron  and 
Erie. 


TRILOBITE 
AMMONITE 
ORTHOCERATITE 
CONULARIA 
TEREBRATUL^E 
PRODUCTS 
ENCRINIS 
CARYOPH1LLIA 
TURBINOLIA 
ASTREA 

CELLULAR  and  chain  MAD- 
REPORES,   STRUES,     and 


RAMOSA,  RETEPORES  and 
FLUSTRA,  in  great  abund- 
ance. Nine  new  varieties  of 

MADREPORES 

LINGULA 

CALYPTR3EA  r 

CERITHEUM 

UNIO 

MYT1LUS 

GRYPHEA 

ARCA 

LILLY  &PEAR  ENCRJNITE, 


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